Names starting with O: Orene to Oswald
300 first names from SSA's national file, part 4 of 5 of the O directory. 119 link to their full record; for the other 181, the row is NameAlmanac's record: the babies given the name since 1880, the years SSA recorded it (5 or more babies of one sex in a year), its peak year and its 2025 births.
Names: SSA national file, 1880-2025, published May 8, 2026. SSA’s notes on the data. SSA lists a name in a year only when 5 or more babies of one sex got it.
Orene to Oswald
| Name | Given to | Babies since 1880 | On record | Peak year | Babies in 2025 |
|---|---|---|---|---|---|
| Orene | Girls | 1,015 | 1897-1959, 54 years | 1919 | under 5 |
| Orentha | Boys | 6 | 1977, 1 year | 1977 | under 5 |
| Orenthal | Boys | 277 | 1968-2005, 19 years | 1977 | under 5 |
| Orenthia | Boys | 5 | 1975, 1 year | 1975 | under 5 |
| Orenthial | Boys | 29 | 1969-1982, 5 years | 1974 | under 5 |
| Oreofeoluwa | Both, 45% girls | 11 | 2016-2018, 2 years | 2018 | under 5 |
| Oreoluwa | Both, 61% girls | 441 | 1999-2025, 27 years | 2016 | 15 |
| Ores | Boys | 12 | 1915-1917, 2 years | 1915 | under 5 |
| Oressa | Girls | 6 | 1890, 1 year | 1890 | under 5 |
| Orest | Boys | 310 | 1916-2025, 33 years | 1952 | 16 |
| Oreste | Boys | 357 | 1912-1987, 42 years | 1921 | under 5 |
| Orestes | Boys | 343 | 1918-2019, 48 years | 1986 | under 5 |
| Oresto | Boys | 17 | 1919-1926, 3 years | 1924 | under 5 |
| Orestus | Boys | 5 | 1916, 1 year | 1916 | under 5 |
| Oreta | Girls | 225 | 1898-1949, 27 years | 1925 | under 5 |
| Oretha | Girls | 1,158 | 1910-1981, 65 years | 1926 | under 5 |
| Oretta | Girls | 221 | 1909-1960, 36 years | 1915 | under 5 |
| Oreva | Girls | 6 | 1922, 1 year | 1922 | under 5 |
| Orey | Boys | 79 | 1915-1996, 9 years | 1987 | under 5 |
| Orfa | Girls | 15 | 1949-1993, 3 years | 1949 | under 5 |
| Orfalinda | Girls | 6 | 1953, 1 year | 1953 | under 5 |
| Orfelinda | Girls | 30 | 1955-1971, 5 years | 1971 | under 5 |
| Orgil | Boys | 5 | 2021, 1 year | 2021 | under 5 |
| Orhaan | Boys | 19 | 2022-2025, 3 years | 2025 | 8 |
| Orhan | Boys | 477 | 1997-2025, 21 years | 2025 | 92 |
| Ori | Both, 18% girls | 1,966 | 1971-2025, 50 years | 2024 | 107 |
| Oria | Girls | 293 | 1906-2025, 40 years | 1915 | 5 |
| Oriah | Girls | 420 | 1999-2025, 25 years | 2023 | 18 |
| Orian | Both, 11% girls | 816 | 1912-2025, 64 years | 2018 | 20 |
| Oriana | Girls | 3,883 | 1966-2025, 59 years | 2003 | 113 |
| Oriane | Girls | 54 | 2002-2025, 8 years | 2018 | 8 |
| Orianna | Girls | 1,378 | 1911-2025, 43 years | 2013 | 53 |
| Orianne | Girls | 5 | 2000, 1 year | 2000 | under 5 |
| Orianthi | Girls | 33 | 2015-2022, 5 years | 2022 | under 5 |
| Orice | Boys | 12 | 1920-1921, 2 years | 1920 | under 5 |
| Orie | Both, 20% girls | 2,156 | 1880-2025, 126 years | 1922 | 11 |
| Oriel | Both, 30% girls | 453 | 1915-2025, 40 years | 2024 | 24 |
| Oriella | Girls | 5 | 2025, 1 year | 2025 | 5 |
| Orielle | Girls | 54 | 1982-2025, 8 years | 2023 | 5 |
| Orien | Boys | 550 | 1903-2025, 66 years | 1919 | 9 |
| Orietta | Girls | 5 | 1922, 1 year | 1922 | under 5 |
| Orik | Boys | 13 | 2017-2019, 2 years | 2017 | under 5 |
| Oril | Boys | 18 | 1917-1927, 3 years | 1921 | under 5 |
| Orilla | Girls | 225 | 1880-1939, 30 years | 1917 | under 5 |
| Orin | Boys | 6,299 | 1880-2025, 146 years | 1920 | 85 |
| Orina | Girls | 5 | 1920, 1 year | 1920 | under 5 |
| Orinda | Girls | 17 | 1921-1950, 3 years | 1949 | under 5 |
| Orine | Girls | 167 | 1911-1949, 19 years | 1921 | under 5 |
| Oriole | Girls | 5 | 1928, 1 year | 1928 | under 5 |
| Orion | Boys | 23,750 | 1880-2025, 128 years | 2018 | 1,030 |
| Oriona | Girls | 8 | 2006, 1 year | 2006 | under 5 |
| Orionna | Girls | 23 | 1997-2008, 4 years | 2003 | under 5 |
| Oris | Both, 12% girls | 1,893 | 1891-2024, 86 years | 1915 | under 5 |
| Orise | Both, 50% girls | 10 | 1919-1953, 2 years | 1919 | under 5 |
| Orisha | Girls | 11 | 1972-1988, 2 years | 1972 | under 5 |
| Orison | Boys | 41 | 1917-1935, 7 years | 1919 | under 5 |
| Orissa | Girls | 61 | 1917-2011, 11 years | 1988 | under 5 |
| Orit | Girls | 124 | 1970-2005, 19 years | 1975 | under 5 |
| Orita | Girls | 15 | 1924-1957, 3 years | 1924 | under 5 |
| Oriya | Girls | 134 | 2004-2025, 17 years | 2024 | 10 |
| Oriyah | Girls | 233 | 2007-2025, 16 years | 2025 | 25 |
| Oriyan | Boys | 10 | 2011-2019, 2 years | 2011 | under 5 |
| Oriyana | Girls | 5 | 2002, 1 year | 2002 | under 5 |
| Orla | Both, 81% girls | 1,485 | 1880-2025, 88 years | 2024 | 70 |
| Orlagh | Girls | 17 | 2011-2022, 3 years | 2011 | under 5 |
| Orlaith | Girls | 49 | 2006-2025, 7 years | 2024 | 6 |
| Orlan | Boys | 960 | 1898-2025, 69 years | 1926 | 7 |
| Orland | Boys | 2,086 | 1885-2023, 99 years | 1922 | under 5 |
| Orlanda | Both, 32% girls | 792 | 1915-1994, 55 years | 1968 | under 5 |
| Orlander | Boys | 160 | 1917-1979, 25 years | 1947 | under 5 |
| Orlandis | Boys | 80 | 1976-2011, 14 years | 1987 | under 5 |
| Orlando | Boys | 49,696 | 1880-2025, 146 years | 1987 | 275 |
| Orlandra | Girls | 14 | 1994-1997, 2 years | 1997 | under 5 |
| Orlandrea | Girls | 8 | 1996, 1 year | 1996 | under 5 |
| Orlandria | Girls | 85 | 1990-2012, 11 years | 1999 | under 5 |
| Orlandus | Boys | 116 | 1962-2008, 19 years | 1971 | under 5 |
| Orlani | Girls | 5 | 2025, 1 year | 2025 | 5 |
| Orlantha | Girls | 11 | 1971-1973, 2 years | 1971 | under 5 |
| Orlean | Girls | 565 | 1896-1970, 52 years | 1928 | under 5 |
| Orlee | Both, 89% girls | 46 | 1919-1986, 7 years | 1923 | under 5 |
| Orleen | Girls | 5 | 1919, 1 year | 1919 | under 5 |
| Orlen | Boys | 259 | 1915-1956, 30 years | 1934 | under 5 |
| Orlena | Girls | 648 | 1881-1983, 75 years | 1921 | under 5 |
| Orlenda | Girls | 5 | 1971, 1 year | 1971 | under 5 |
| Orlene | Girls | 402 | 1912-1971, 40 years | 1921 | under 5 |
| Orletta | Girls | 37 | 1918-1938, 5 years | 1918 | under 5 |
| Orley | Boys | 459 | 1880-1963, 46 years | 1918 | under 5 |
| Orli | Girls | 512 | 1974-2025, 37 years | 2024 | 22 |
| Orlidia | Girls | 5 | 1944, 1 year | 1944 | under 5 |
| Orlie | Boys | 357 | 1885-1961, 40 years | 1918 | under 5 |
| Orlin | Boys | 1,683 | 1908-2025, 96 years | 1932 | 22 |
| Orlinda | Girls | 321 | 1915-1974, 40 years | 1946 | under 5 |
| Orline | Girls | 58 | 1911-1935, 9 years | 1922 | under 5 |
| Orlis | Boys | 5 | 1933, 1 year | 1933 | under 5 |
| Orlo | Boys | 920 | 1881-2022, 62 years | 1919 | under 5 |
| Orlondo | Boys | 76 | 1962-2001, 12 years | 1970 | under 5 |
| Orly | Girls | 824 | 1964-2025, 53 years | 2013 | 29 |
| Orlyn | Boys | 287 | 1915-2023, 33 years | 1923 | under 5 |
| Orma | Girls | 699 | 1890-1950, 52 years | 1921 | under 5 |
| Ormah | Girls | 11 | 1928-1929, 2 years | 1928 | under 5 |
| Ormal | Boys | 24 | 1917-1928, 4 years | 1917 | under 5 |
| Orman | Boys | 886 | 1908-1984, 57 years | 1923 | under 5 |
| Ormand | Boys | 206 | 1912-1959, 27 years | 1924 | under 5 |
| Ormani | Girls | 21 | 2025, 1 year | 2025 | 21 |
| Ormi | Girls | 5 | 1916, 1 year | 1916 | under 5 |
| Ormond | Boys | 513 | 1903-2000, 51 years | 1917 | under 5 |
| Orna | Girls | 42 | 1924-1973, 7 years | 1965 | under 5 |
| Ornella | Girls | 240 | 1968-2025, 33 years | 2013 | 6 |
| Orneta | Girls | 6 | 1918, 1 year | 1918 | under 5 |
| Ornie | Boys | 10 | 1924-1961, 2 years | 1924 | under 5 |
| Oro | Boys | 5 | 2024, 1 year | 2024 | under 5 |
| Oron | Boys | 83 | 1888-1947, 11 years | 1921 | under 5 |
| Oronde | Boys | 292 | 1971-2008, 25 years | 1973 | under 5 |
| Ororo | Girls | 5 | 2021, 1 year | 2021 | under 5 |
| Orothy | Girls | 5 | 1925, 1 year | 1925 | under 5 |
| Orpah | Girls | 107 | 1899-1950, 15 years | 1923 | under 5 |
| Orpha | Girls | 5,974 | 1880-2024, 111 years | 1917 | under 5 |
| Orpheus | Boys | 81 | 1916-2024, 13 years | 1968 | under 5 |
| Orphia | Girls | 101 | 1897-1925, 15 years | 1918 | under 5 |
| Orphie | Girls | 24 | 1915-1922, 4 years | 1915 | under 5 |
| Orphus | Boys | 11 | 1896-1914, 2 years | 1914 | under 5 |
| Orquidea | Girls | 55 | 1977-2017, 9 years | 1990 | under 5 |
| Orquidia | Girls | 44 | 1980-2009, 8 years | 1980 | under 5 |
| Orr | Boys | 50 | 1887-2006, 9 years | 1998 | under 5 |
| Orra | Both, 88% girls | 146 | 1883-1928, 21 years | 1919 | under 5 |
| Orral | Boys | 5 | 1920, 1 year | 1920 | under 5 |
| Orran | Boys | 15 | 1924-2009, 3 years | 1924 | under 5 |
| Orrel | Boys | 10 | 1916-1920, 2 years | 1916 | under 5 |
| Orrell | Boys | 10 | 1916-1922, 2 years | 1916 | under 5 |
| Orren | Boys | 925 | 1880-2025, 98 years | 1923 | 7 |
| Orrey | Boys | 5 | 1986, 1 year | 1986 | under 5 |
| Orrick | Boys | 6 | 2017, 1 year | 2017 | under 5 |
| Orrie | Both, 32% girls | 988 | 1880-2007, 86 years | 1918 | under 5 |
| Orrin | Boys | 5,985 | 1880-2025, 146 years | 1915 | 62 |
| Orris | Boys | 988 | 1894-2022, 57 years | 1918 | under 5 |
| Orry | Boys | 383 | 1985-2025, 30 years | 1986 | 6 |
| Orryn | Boys | 20 | 2014-2022, 3 years | 2022 | under 5 |
| Orsen | Boys | 21 | 2011-2025, 4 years | 2022 | 5 |
| Orsola | Girls | 5 | 1920, 1 year | 1920 | under 5 |
| Orson | Boys | 2,714 | 1880-2025, 129 years | 2023 | 126 |
| Ortega | Boys | 6 | 1958, 1 year | 1958 | under 5 |
| Ortencia | Girls | 316 | 1919-1993, 47 years | 1949 | under 5 |
| Ortensia | Girls | 43 | 1928-1976, 8 years | 1928 | under 5 |
| Ortha | Girls | 254 | 1904-1942, 26 years | 1923 | under 5 |
| Ortis | Boys | 16 | 1919-1938, 3 years | 1921 | under 5 |
| Ortiz | Boys | 7 | 1976, 1 year | 1976 | under 5 |
| Orton | Boys | 210 | 1905-1951, 23 years | 1921 | under 5 |
| Ortrude | Girls | 6 | 1916, 1 year | 1916 | under 5 |
| Orum | Boys | 5 | 1918, 1 year | 1918 | under 5 |
| Orus | Boys | 16 | 1915-1922, 3 years | 1922 | under 5 |
| Orva | Both, 83% girls | 613 | 1882-1967, 50 years | 1916 | under 5 |
| Orval | Boys | 7,928 | 1880-1995, 110 years | 1918 | under 5 |
| Orvall | Boys | 47 | 1914-1924, 8 years | 1924 | under 5 |
| Orvalle | Boys | 16 | 1916-1919, 3 years | 1916 | under 5 |
| Orvan | Boys | 143 | 1915-1950, 20 years | 1926 | under 5 |
| Orvel | Boys | 1,157 | 1888-1972, 61 years | 1919 | under 5 |
| Orvell | Boys | 135 | 1915-1953, 20 years | 1922 | under 5 |
| Orvella | Girls | 68 | 1913-1951, 12 years | 1913 | under 5 |
| Orven | Boys | 42 | 1916-1951, 7 years | 1917 | under 5 |
| Orvetta | Girls | 159 | 1910-1960, 22 years | 1923 | under 5 |
| Orvid | Boys | 27 | 1918-1928, 5 years | 1927 | under 5 |
| Orvie | Boys | 136 | 1912-1957, 22 years | 1918 | under 5 |
| Orvil | Boys | 1,935 | 1897-1991, 74 years | 1921 | under 5 |
| Orvile | Boys | 118 | 1914-1943, 17 years | 1927 | under 5 |
| Orvill | Boys | 224 | 1912-1951, 25 years | 1922 | under 5 |
| Orvilla | Girls | 238 | 1905-1958, 30 years | 1917 | under 5 |
| Orville | Boys | 35,220 | 1880-2025, 146 years | 1920 | 14 |
| Orvin | Boys | 1,140 | 1890-2024, 69 years | 1917 | under 5 |
| Orvind | Boys | 5 | 1922, 1 year | 1922 | under 5 |
| Orvis | Boys | 940 | 1885-1961, 51 years | 1920 | under 5 |
| Orvo | Boys | 6 | 1914, 1 year | 1914 | under 5 |
| Orwin | Boys | 49 | 1915-1928, 7 years | 1920 | under 5 |
| Ory | Boys | 147 | 1919-2011, 14 years | 1986 | under 5 |
| Orya | Girls | 33 | 2010-2025, 5 years | 2024 | 6 |
| Oryah | Girls | 6 | 2021, 1 year | 2021 | under 5 |
| Oryan | Boys | 1,130 | 1975-2025, 47 years | 2009 | 36 |
| Oryana | Girls | 10 | 2017-2022, 2 years | 2017 | under 5 |
| Oryen | Boys | 7 | 2018, 1 year | 2018 | under 5 |
| Oryn | Boys | 215 | 2008-2025, 14 years | 2018 | 9 |
| Oryon | Boys | 122 | 2002-2023, 16 years | 2017 | under 5 |
| Orysia | Girls | 11 | 1950-1952, 2 years | 1950 | under 5 |
| Osa | Both, 89% girls | 770 | 1880-2025, 68 years | 1918 | 9 |
| Osagie | Boys | 36 | 1999-2016, 7 years | 2013 | under 5 |
| Osahon | Boys | 16 | 1999-2016, 3 years | 2016 | under 5 |
| Osai | Boys | 5 | 2024, 1 year | 2024 | under 5 |
| Osaiah | Boys | 6 | 2024, 1 year | 2024 | under 5 |
| Osaid | Boys | 19 | 2020-2025, 3 years | 2024 | 5 |
| Osama | Boys | 979 | 1968-2025, 52 years | 1999 | 18 |
| Osamah | Boys | 101 | 1977-2001, 14 years | 1998 | under 5 |
| Osamu | Boys | 94 | 1920-1997, 14 years | 1925 | under 5 |
| Osanna | Girls | 11 | 2000-2024, 2 years | 2024 | under 5 |
| Osaretin | Boys | 11 | 2000-2020, 2 years | 2000 | under 5 |
| Osariemen | Girls | 5 | 2016, 1 year | 2016 | under 5 |
| Osaro | Boys | 7 | 2021, 1 year | 2021 | under 5 |
| Osayd | Boys | 25 | 2022-2025, 3 years | 2024 | 5 |
| Osaze | Boys | 132 | 1991-2024, 19 years | 2007 | under 5 |
| Osbaldo | Boys | 3,092 | 1928-2025, 71 years | 2002 | 14 |
| Osbert | Boys | 11 | 1971-2008, 2 years | 2008 | under 5 |
| Osbie | Boys | 12 | 1918-1919, 2 years | 1919 | under 5 |
| Osbon | Boys | 30 | 1915-1929, 5 years | 1927 | under 5 |
| Osborn | Boys | 603 | 1884-2025, 65 years | 1923 | 6 |
| Osborne | Boys | 1,754 | 1880-2025, 117 years | 1915 | 22 |
| Osbourne | Boys | 64 | 2002-2025, 10 years | 2025 | 11 |
| Osburn | Boys | 51 | 1916-1939, 8 years | 1916 | under 5 |
| Osby | Boys | 150 | 1912-1970, 22 years | 1922 | under 5 |
| Oscar | Boys | 214,168 | 1880-2025, 146 years | 2006 | 1,620 |
| Oscardaniel | Boys | 5 | 1996, 1 year | 1996 | under 5 |
| Oscarjr | Boys | 5 | 2005, 1 year | 2005 | under 5 |
| Osceola | Both, 71% girls | 209 | 1906-2009, 31 years | 1917 | under 5 |
| Oscer | Boys | 26 | 1921-1934, 5 years | 1932 | under 5 |
| Osciel | Boys | 5 | 2008, 1 year | 2008 | under 5 |
| Osco | Boys | 12 | 1928-1929, 2 years | 1928 | under 5 |
| Oscor | Boys | 12 | 1916-1933, 2 years | 1916 | under 5 |
| Ose | Boys | 5 | 1986, 1 year | 1986 | under 5 |
| Osean | Both, 14% girls | 50 | 2008-2024, 6 years | 2023 | under 5 |
| Oseas | Boys | 408 | 1990-2025, 30 years | 2024 | 24 |
| Osee | Girls | 11 | 1898-1923, 2 years | 1898 | under 5 |
| Osei | Boys | 238 | 1974-2025, 35 years | 1981 | 5 |
| Oseias | Boys | 333 | 2016-2025, 10 years | 2017 | 40 |
| Oseph | Boys | 67 | 1969-1988, 8 years | 1987 | under 5 |
| Osgood | Boys | 18 | 1915-1919, 3 years | 1918 | under 5 |
| Osha | Both, 77% girls | 365 | 1924-2024, 32 years | 1993 | under 5 |
| Oshae | Boys | 249 | 1991-2025, 26 years | 1994 | 7 |
| Oshai | Both, 26% girls | 38 | 1992-2024, 6 years | 1993 | under 5 |
| Oshan | Boys | 5 | 2025, 1 year | 2025 | 5 |
| Oshane | Boys | 67 | 1996-2025, 10 years | 2009 | 6 |
| Oshanique | Girls | 5 | 2001, 1 year | 2001 | under 5 |
| Oshanna | Girls | 5 | 1978, 1 year | 1978 | under 5 |
| Oshaun | Boys | 5 | 2023, 1 year | 2023 | under 5 |
| Oshawn | Boys | 28 | 1993-2023, 5 years | 1993 | under 5 |
| Oshay | Boys | 439 | 1980-2024, 34 years | 1992 | under 5 |
| Oshaye | Boys | 10 | 1994-1995, 2 years | 1994 | under 5 |
| Oshea | Boys | 1,288 | 1979-2025, 41 years | 2019 | 54 |
| Oshean | Boys | 11 | 2024-2025, 2 years | 2025 | 6 |
| Osheana | Girls | 11 | 1997-2000, 2 years | 2000 | under 5 |
| Osheanna | Girls | 22 | 1990-2007, 4 years | 2001 | under 5 |
| Oshen | Boys | 160 | 2000-2025, 20 years | 2023 | 6 |
| Osher | Boys | 227 | 1958-2025, 29 years | 2024 | 9 |
| Oshia | Girls | 11 | 1993-1997, 2 years | 1993 | under 5 |
| Oshian | Both, 50% girls | 10 | 2023, 1 year | 2023 | under 5 |
| Oshiana | Girls | 7 | 1997, 1 year | 1997 | under 5 |
| Oshie | Girls | 5 | 1908, 1 year | 1908 | under 5 |
| Oshin | Both, 38% girls | 29 | 2019-2025, 5 years | 2024 | 6 |
| Oshua | Boys | 95 | 1978-1989, 11 years | 1986 | under 5 |
| Oshun | Both, 80% girls | 265 | 2002-2025, 11 years | 2022 | 34 |
| Oshyn | Both, 82% girls | 94 | 2003-2025, 11 years | 2024 | 8 |
| Oshynn | Girls | 11 | 2023-2024, 2 years | 2024 | under 5 |
| Osia | Girls | 30 | 1913-1951, 5 years | 1920 | under 5 |
| Osiah | Boys | 346 | 1999-2025, 16 years | 2025 | 54 |
| Osian | Boys | 50 | 2017-2025, 7 years | 2017 | 9 |
| Osiana | Girls | 5 | 2003, 1 year | 2003 | under 5 |
| Osias | Boys | 434 | 2004-2025, 21 years | 2025 | 43 |
| Osie | Both, 64% girls | 2,102 | 1880-1982, 88 years | 1927 | under 5 |
| Osiel | Boys | 2,995 | 1970-2025, 54 years | 2023 | 123 |
| Osier | Boys | 10 | 2025, 1 year | 2025 | 10 |
| Osinachi | Both, 29% girls | 140 | 2009-2024, 12 years | 2016 | under 5 |
| Osiria | Girls | 5 | 2015, 1 year | 2015 | under 5 |
| Osiris | Both, 20% girls | 4,475 | 1970-2025, 55 years | 2023 | 215 |
| Osirus | Boys | 69 | 1997-2024, 12 years | 2003 | under 5 |
| Osirys | Girls | 10 | 2001-2002, 2 years | 2001 | under 5 |
| Osiyah | Boys | 6 | 2024, 1 year | 2024 | under 5 |
| Osiyo | Girls | 57 | 2016-2025, 7 years | 2023 | 10 |
| Oskar | Boys | 3,241 | 1916-2025, 56 years | 2016 | 93 |
| Osker | Boys | 210 | 1898-2007, 25 years | 1920 | under 5 |
| Osleen | Girls | 5 | 2023, 1 year | 2023 | under 5 |
| Osler | Boys | 5 | 1924, 1 year | 1924 | under 5 |
| Oslin | Girls | 11 | 2023-2024, 2 years | 2023 | under 5 |
| Oslo | Boys | 581 | 2007-2025, 18 years | 2022 | 78 |
| Osman | Boys | 3,893 | 1917-2025, 61 years | 2022 | 181 |
| Osmani | Boys | 94 | 1998-2023, 14 years | 2022 | under 5 |
| Osmany | Boys | 165 | 1991-2025, 22 years | 2012 | 5 |
| Osmar | Boys | 2,304 | 1973-2025, 49 years | 2008 | 59 |
| Osmara | Girls | 346 | 1989-2025, 32 years | 2004 | 12 |
| Osmari | Girls | 5 | 2025, 1 year | 2025 | 5 |
| Osmary | Girls | 51 | 2005-2024, 8 years | 2024 | under 5 |
| Osmel | Boys | 132 | 1993-2023, 14 years | 2007 | under 5 |
| Osmer | Boys | 12 | 1918-1922, 2 years | 1918 | under 5 |
| Osmin | Boys | 549 | 1983-2025, 42 years | 2006 | 12 |
| Osmo | Boys | 13 | 1915-1917, 2 years | 1915 | under 5 |
| Osmon | Boys | 5 | 1979, 1 year | 1979 | under 5 |
| Osmond | Boys | 470 | 1912-2025, 58 years | 2022 | 13 |
| Osmund | Boys | 31 | 1957-2025, 5 years | 1957 | 7 |
| Osnas | Girls | 5 | 2010, 1 year | 2010 | under 5 |
| Oso | Boys | 61 | 2018-2025, 7 years | 2023 | 12 |
| Osric | Boys | 135 | 1972-2025, 22 years | 2015 | 10 |
| Ossama | Boys | 23 | 1992-2001, 4 years | 2000 | under 5 |
| Ossian | Boys | 106 | 2005-2025, 12 years | 2023 | 8 |
| Ossie | Both, 64% girls | 4,594 | 1880-2014, 116 years | 1919 | under 5 |
| Ossiel | Boys | 111 | 1993-2024, 16 years | 1996 | under 5 |
| Ostap | Boys | 47 | 2013-2025, 6 years | 2025 | 11 |
| Ostara | Girls | 75 | 2011-2024, 8 years | 2019 | under 5 |
| Osteen | Boys | 11 | 2008-2017, 2 years | 2017 | under 5 |
| Ostell | Boys | 7 | 1927, 1 year | 1927 | under 5 |
| Osten | Boys | 187 | 1992-2024, 23 years | 2013 | under 5 |
| Ostin | Boys | 464 | 1992-2025, 32 years | 2023 | 23 |
| Ostyn | Boys | 30 | 1998-2023, 5 years | 2023 | under 5 |
| Osualdo | Boys | 387 | 1957-2007, 43 years | 1993 | under 5 |
| Osvaldo | Boys | 14,538 | 1917-2025, 84 years | 2004 | 130 |
| Osvin | Boys | 82 | 2003-2025, 13 years | 2012 | 7 |
| Oswald | Boys | 4,407 | 1880-2025, 146 years | 1916 | 67 |
Order: alphabetical by the name as SSA spells it. Given to: the share of girls among all babies given the name.