| Gamecock Athletes | | Name | Begin | End | City | State | Sport |
| . O'Brien | 1942 | 1943 | | | Basketball; |
| Aidan O'Brien | 2018 | 2018 | Asheville | NC | Soccer; |
| Chick O'Brien | 1938 | 1938 | | | Basketball; |
| Katie O'Brien | 2013 | 2017 | Davidson | NC | Swimming/Diving; |
| Maquala O'Brien | 2011 | 2013 | Chapin | SC | Swimming/Diving; |
Matt O'Brien | 2010 | 2011 | New Milford | NJ | Football; | . O'Bryan | 1901 | 1901 | | | Baseball; | Paul O'Cain | 1959 | 1959 | Orangeburg | SC | Football; | G.B. O'Connell | 1943 | 1943 | Highland Park | IL | Football; | Greg O'Conner | 1987 | 1987 | | | Tennis; | | Bob O'Connor | 1981 | 1981 | | | Soccer; |
| Jake O'Connor | 2020 | 2020 | Cary | NC | Soccer; |
| Tom O'Connor | 1984 | 1985 | East Patchogue | NY | Football; |
| Evan O'Dell | 2007 | 2010 | Duluth | GA | Soccer; |
| Firpo O'Dell | 1932 | 1932 | | | Football; |
Erin O'Donnell | 1997 | 1997 | Ogallala | NE | Volleyball; | Kathy O'Donnell | 1983 | 1984 | | | Swimming/Diving; | Mary O'Donnell | 1991 | 1992 | | | Swimming/Diving; | Margaret O'Grady | 1985 | 1985 | | | Tennis; | Maura O'Grady | 1982 | 1985 | | | Swimming/Diving; | | Larry O'Hagan | 1976 | 1976 | Augusta | GA | Football; |
| Bob O'Harra | 1969 | 1970 | Florence | SC | Football; |
| Bobby O'Harra | 1942 | 1947 | Florence | SC | Football; |
| Harrison O'Keefe | 2013 | 2018 | Salem | VA | Tennis; |
| Ryan O'Neill | 1996 | 1999 | | | Soccer; |
Chris O'Sullivan | 1989 | 1992 | | | Swimming/Diving; | Laura O'Sullivan | 2003 | 2005 | | | Equestrian; | Terry O'Toole | 1984 | 1984 | | | Track & Field; | Brooke Obeck | 2011 | 2013 | Glen Allen | VA | Swimming/Diving; | Leslie Och | 1983 | 1984 | | | Swimming/Diving; | | Karsen Ochs | 2020 | 2020 | Macon | GA | Softball; |
| Page Odle | 1981 | 1981 | Santa Paula | CA | Baseball; |
| Sean Odom | 2014 | 2015 | Orangeburg | SC | Football; |
| Paul Odomirok | 1972 | 1975 | Hollywood | FL | Football; |
| India Odum | 2001 | 2004 | | | Track & Field; |
Andre Offing | 1996 | 2000 | Houston | TX | Football; | Willie Offord | 1997 | 2001 | Palatka | FL | Football; | Marvin Oglesby | 1987 | 1987 | Decatur | GA | Football; | R.C. Oglesby | 1911 | 1912 | Cowpens | SC | Baseball; Football; | Kelsey Oh | 2018 | 2019 | Verona | NJ | Softball; | | Mattias Ohlsson | 1997 | 1998 | | | Track & Field; |
| Ainhoa Olarra | 2014 | 2018 | San Sebastian | | Golf; |
| Andria Oleszczuk | 2001 | 2001 | | | Swimming/Diving; |
| Stanislav Olijar | 1999 | 1999 | | | Track & Field; |
| Reid Oliphant | 2011 | 2011 | Spartanburg | SC | Track & Field; |
Matt Oliveira | 2019 | 2019 | Watchung | NJ | Football; | Gene Oliver | 1903 | 1905 | Centenary | SC | Baseball; | Gene Oliver | 1900 | 1903 | | | Football; | Len Oliver | 1978 | 1979 | Charlotte | NC | Football; | Tommy Oliver | 1976 | 1977 | Atlanta | GA | Football; | | Walter Ollic | 1954 | 1955 | Charleston | SC | Football; |
| . Ollie | 1953 | 1954 | | | Basketball; |
| Erin Olsen | 1998 | 1998 | | | Swimming/Diving; |
| Petra Olsen | 2011 | 2014 | Malmo | | Track & Field; |
| Jacob Olson | 2017 | 2019 | Monroe | GA | Baseball; |
Lindsey Olson | 2008 | 2012 | Charleston | SC | Swimming/Diving; | Nicholas Olson | 2007 | 2008 | Charleston | SC | Swimming/Diving; | Ben Olszewski | 1964 | 1964 | | | Football; | Funlayo Oluwole | 2016 | 2018 | Chesapeake | VA | Track & Field; | Eyong Oma | 2011 | 2011 | Washington | DC | Track & Field; | | Jennie Ondo | 1996 | 1999 | | | Soccer; |
| Colleen Openshaw | 2016 | 2018 | St. Johns | FL | Track & Field; |
| Bob Orkis | 1976 | 1978 | Gahanna | OH | Football; |
| Burt Orr | 1941 | 1942 | Columbia | SC | Basketball; |
| Chris Orr | 1994 | 1995 | Estill | SC | Football; |
John Orr | 1970 | 1970 | Hendersonville | NC | Football; | John Orr | 1960 | 1962 | | | Golf; | Katie Orr | 2000 | 2001 | | | Track & Field; | Wally Orrel | 1966 | 1968 | Savannah | GA | Football; | Carolyn Ortega | 1999 | 2002 | | | Soccer; | | Perry Orth | 2013 | 2016 | Ponte Vedra | FL | Football; |
| Jamie Osborn | 2010 | 2012 | Greenville | SC | Swimming/Diving; |
| Rut Osborne | 1941 | 1941 | Orangeburg | SC | Football; |
| Rut L. Osborne | 1915 | 1917 | | | Football; |
| Randy Osga | 1976 | 1976 | | | Tennis; |
Denny Ostazewski | 1963 | 1963 | Hammond | IN | Basketball; | Soren Ostberg | 1983 | 1984 | | | Swimming/Diving; | Casey Ostein | 2006 | 2006 | | | Track & Field; | Kazuya Otani | 2003 | 2006 | Port Washington | NY | Tennis; | Emma Otten | 2017 | 2018 | Cincinnati | OH | Swimming/Diving; | | . Ottinger | 1944 | 1944 | | | Baseball; |
| Dawn Otto | 1980 | 1983 | | | Tennis; |
| Larry Otto | 1973 | 1973 | Raleigh | NC | Football; |
| Kes Outhwaite | 1994 | 1996 | | | Soccer; |
| Jazuun Outlaw | 2017 | 2019 | Dillon | SC | Football; |
William Outlaw | 1941 | 1941 | | | Baseball; | Bill Ouzts | 1931 | 1933 | Columbia | SC | Baseball; | Kenneth Ouzts | 1934 | 1934 | | | Baseball; Basketball; | Brian Ovelette | 1986 | 1986 | | | Tennis; | David Ovelson | 2005 | 2008 | Edmonton | ALB | Swimming/Diving; | | Megan Overberg | 2014 | 2018 | Hillsboro | OH | Equestrian; |
| Anthony Overstreet | 1996 | 2000 | Atlanta | GA | Football; |
| Charlie Overstreet | 1961 | 1961 | North Augusta | SC | Football; |
| Alexander Overton | 2018 | 2018 | Cedar Rapids | IA | Swimming/Diving; |
| Bill Overton | 1937 | 1937 | | | Basketball; |
Allen Owen | 1967 | 1967 | Columbus | GA | Football; | Sam Owen | 1910 | 1913 | St. Matthews | SC | Baseball; | Calvin Owens | 1994 | 1997 | North Augusta | SC | Football; | Charlie Owens | 1939 | 1939 | | | Basketball; | Christian Owens | 2015 | 2015 | Griffin | GA | Football; | | Drew Owens | 2011 | 2014 | Charlotte | NC | Football; |
| Harold Owens | 1948 | 1948 | Sumter | SC | Football; |
| Madison Owens | 2019 | 2019 | Dillon | SC | Softball; |
| Roy Owens | 1953 | 1954 | | | Golf; |
| Steve Owens | 1992 | 1995 | | | Track & Field; |
Tom Owens | 1967 | 1971 | The Bronx | NY | Basketball; | Brittany Oxley | 2014 | 2018 | Folsom | CA | Swimming/Diving; | Jaima Oxley | 1977 | 1979 | Columbia | SC | Basketball; | Ellen Oxrieder | 1980 | 1983 | | | Tennis; | John (Red) Ozburn | 1946 | 1948 | Andrews | SC | Football; |