Opposition Players
| Full Name sorted descending | Birthdate sortable | Era | Club(s) sortable | Apps sortable | Goals sortable |
|---|---|---|---|---|---|
| Frank Onyeka | 1 Jan 1998 | 2020-21 – 2025-26 | Brentford, FC Midtjylland | 8 | 0 |
| Udo Onwere | 9 Nov 1971 | 1993-94 | Fulham | 2 | 0 |
| Kivrak Onur | 1 Jan 1988 | 2010-11 | Trabzonspor | 2 | 0 |
| Nedum Onuoha | 12 Nov 1986 | 2004-05 – 2014-15 | Manchester City, Queens Park Rangers, Sunderland | 12 | 0 |
| Paul Onuachu | 28 May 1994 | 2019-20 – 2024-25 | Southampton, KRC Genk | 5 | 0 |
| Roberto Onorati | 5 Feb 1966 | 1991-92 | Genoa | 2 | 0 |
| Viktor Onopko | 14 Oct 1969 | 1992-93 | Spartak Moscow | 2 | 0 |
| Josh Onomah | 27 Apr 1997 | 2016-17 | Tottenham Hotspur | 2 | 0 |
| Daniel Onofras | 17 Aug 1980 | 2009-10 | Unirea Urziceni | 2 | 0 |
| Ákos Onódi | 2 Sept 2001 | 2020-21 | Aston Villa | 1 | 0 |
| Luke O'Nien | 21 Nov 1994 | 2025-26 | Sunderland | 1 | 0 |
| Tibor Onhausz | 22 Jul 1955 | 1974-75 | Ferencvaros | 1 | 0 |
| Jérôme Onguéné | 22 Dec 1997 | 2019-20 | Red Bull Salzburg | 2 | 0 |
| Martin O'Neill | 1 Mar 1952 | 1977-78 – 1983-84 | Nottingham Forest, Norwich City, Notts County | 16 | 1 |
| Michael O'Neill | 5 Jul 1969 | 1988-89 | Newcastle United | 1 | 0 |
| Les O'Neill | 4 Dec 1943 | 1972-73 – 1976-77 | Carlisle United | 7 | 1 |
| Keith O'Neill | 16 Feb 1976 | 1999-2000 – 2000-01 | Middlesbrough | 2 | 0 |
| John O'Neill | 11 Mar 1958 | 1980-81 – 1986-87 | Leicester City | 9 | 0 |
| James J O'Neill | 24 Feb 1952 | 1979-80 | Chesterfield | 1 | 0 |
| Jimmy O'Neill | 13 Oct 1931 | 1950-51 – 1961-62 | Stoke City, Everton | 5 | 0 |
| Harry O'Neill | 1919-20 | Sheffield Wednesday | 1 | 0 | |
| Alan O'Neill | 13 Nov 1937 | 1958-59 – 1959-60 | Sunderland | 2 | 0 |
| Aiden O'Neill | 4 Jul 1998 | 2016-17 | Burnley | 1 | 0 |
| Tommy O'Neil | 25 Oct 1952 | 1971-72 – 1979-80 | Manchester United, Tranmere Rovers | 6 | 0 |
| Gary O'Neil | 18 May 1983 | 2004-05 – 2015-16 | Portsmouth, Middlesbrough, West Ham United, Norwich City | 14 | 0 |
| Brian O'Neil | 4 Jan 1944 | 1963-64 – 1973-74 | Burnley, Southampton | 22 | 2 |
| Amadou Onana | 16 Aug 2001 | 2022-23 – 2025-26 | Everton, Aston Villa | 6 | 0 |
| André Onana | 2 Apr 1996 | 2020-21 – 2024-25 | Manchester United, Ajax | 7 | 0 |
| Manny Omoyinmi | 28 Dec 1977 | 1997-98 | West Ham United | 1 | 0 |
| Andrew Omobamidele | 23 Jun 2002 | 2021-22 – 2023-24 | Nottingham Forest, Norwich City | 2 | 0 |
| Kenneth Omeruo | 17 Oct 1993 | 2014-15 | Middlesbrough | 1 | 0 |
| Callum Olusesi | 11 Mar 2007 | 2025-26 | Tottenham Hotspur | 1 | 0 |
| Sebastian Olszar | 10 Dec 1981 | 2003-04 | Portsmouth | 1 | 0 |
| Jonas Olsson | 10 Mar 1983 | 2008-09 – 2016-17 | West Bromwich Albion | 14 | 1 |
| Marcus Olsson | 17 May 1988 | 2011-12 – 2016-17 | Derby County, Blackburn Rovers | 2 | 0 |
| Martin Olsson | 17 May 1988 | 2009-10 – 2017-18 | Blackburn Rovers, Swansea City, Norwich City | 12 | 1 |
| Tommy Olsen | 13 Jan 1913 | 1935-36 | Swansea City | 1 | 0 |
| Trond Olsen | 1974-75 | Strømsgodset | 2 | 0 | |
| Jesper Olsen | 20 Mar 1961 | 1984-85 – 1988-89 | Manchester United | 11 | 0 |
| Finn Olsen | 1974-75 | Strømsgodset | 2 | 0 | |
| Egil Olsen | 23 Jul 1948 | 1974-75 | Strømsgodset | 2 | 0 |
| Robin Olsen | 1 Aug 1990 | 2022-23 | Aston Villa | 1 | 0 |
| Seyi Olofinjana | 30 Jun 1980 | 2008-09 | Stoke City | 1 | 0 |
| Ian Olney | 17 Dec 1969 | 1988-89 – 1992-93 | Aston Villa, Oldham Athletic | 6 | 2 |
| Ben Olney | 30 Mar 1899 | 1926-27 – 1929-30 | Derby County, Aston Villa | 5 | 0 |
| Dani Olmo | 7 May 1998 | 2020-21 | RasenBallsport Leipzig | 2 | 0 |
| Billy Ollis | 12 Aug 1871 | 1893-94 – 1894-95 | Birmingham City | 4 | 0 |
| Ruben Olivera | 4 May 1983 | 2004-05 | Juventus | 1 | 0 |
| Mathías Olivera | 31 Oct 1997 | 2022-23 | Napoli | 2 | 0 |
| Len Oliver | 1 Aug 1905 | 1925-26 – 1933-34 | Fulham | 3 | 0 |
| Sid Oliver | 1894-95 – 1895-96 | Birmingham City | 3 | 0 | |
| Ken Oliver | 10 Aug 1924 | 1948-49 – 1952-53 | Derby County | 6 | 0 |
| Harry Oliver | 16 Feb 1921 | 1946-47 | Brentford | 1 | 0 |
| Gavin Oliver | 6 Sept 1962 | 1984-85 | Sheffield Wednesday | 1 | 0 |
| Oliveira | 8 Jun 1958 | 1983-84 – 1984-85 | Benfica | 4 | 0 |
| Sérgio Oliveira | 2 Jun 1992 | 2017-18 – 2021-22 | FC Porto | 4 | 0 |
| Sunday Oliseh | 14 Sept 1974 | 2001-02 | Borussia Dortmund | 1 | 0 |
| Michael Olise | 12 Dec 2001 | 2021-22 – 2023-24 | Crystal Palace | 6 | 0 |
| Syd O'Linn | 5 May 1927 | 1947-48 – 1953-54 | Charlton Athletic | 5 | 1 |
| Mieczyslaw Olesiak | 10 Dec 1954 | 1975-76 | Slask Wroclaw | 2 | 0 |
| Saloman Olembe | 8 Dec 1980 | 2003-04 | Leeds United | 1 | 0 |
| Robert Olejnik | 26 Nov 1986 | 2015-16 | Exeter City | 2 | 0 |
| Oleguer | 2 Feb 1980 | 2006-07 | Barcelona | 1 | 0 |
| Stephen O'Leary | 2 Feb 1985 | 2007-08 | Luton Town | 1 | 0 |
| Donal O'Leary | 24 Jun 1936 | 1955-56 | Blackburn Rovers | 1 | 0 |
| David O'Leary | 2 May 1958 | 1975-76 – 1993-94 | Arsenal, Leeds United | 45 | 0 |
| Max O'Leary | 10 Oct 1996 | 2019-20 | Shrewsbury Town | 2 | 0 |
| Wilfred Oldham | 1900-01 | Blackburn Rovers | 1 | 0 | |
| George Oldham | 20 Apr 1920 | 1938-39 | Stoke City | 1 | 0 |
| John Oldfield | 19 Aug 1943 | 1969-70 | Wolves | 1 | 0 |
| David Oldfield | 30 May 1968 | 1987-88 – 1994-95 | Manchester City, Luton Town, Leicester City | 5 | 1 |
| Percy Oldacre | 25 Oct 1892 | 1921-22 | Sheffield United | 1 | 0 |
| Victor Olatunji | 5 Sept 1999 | 2023-24 | Sparta Prague | 1 | 0 |
| Rafael Olara | 26 May 1978 | 2006-07 | Maccabi Haifa | 2 | 0 |
| Masaya Okugawa | 14 Apr 1996 | 2019-20 | Red Bull Salzburg | 2 | 0 |
| Godwin Okpara | 20 Sept 1972 | 1997-98 | Strasbourg | 2 | 0 |
| Jores Okore | 11 Aug 1992 | 2013-14 – 2015-16 | Aston Villa | 4 | 0 |
| Miroslaw Okonski | 8 Dec 1958 | 1984-85 | Lech Poznan | 2 | 0 |
| Paul Okon | 5 Apr 1972 | 2000-01 – 2002-03 | Middlesbrough, Leeds United | 3 | 0 |
| Caleb Okoli | 13 Jul 2001 | 2024-25 | Leicester City | 1 | 0 |
| Jay Jay Okocha | 14 Aug 1973 | 2002-03 – 2005-06 | Bolton Wanderers | 6 | 1 |
| Jarkko Okkonen | 8 Sept 1978 | 2001-02 | Haka | 2 | 0 |
| Giannakis Okkas | 11 Feb 1977 | 2004-05 | Olympiacos | 2 | 0 |
| Richard O'Kelly | 8 Jan 1957 | 1983-84 | Walsall | 2 | 0 |
| Corey O'Keeffe | 5 Jun 1998 | 2025-26 | Barnsley | 1 | 0 |
| Vince O'Keefe | 2 Apr 1957 | 1979-80 | Exeter City | 1 | 0 |
| Eamonn O'Keefe | 13 Oct 1953 | 1980-81 – 1981-82 | Everton | 4 | 0 |
| Stuart O'Keefe | 4 Mar 1991 | 2013-14 | Crystal Palace | 1 | 0 |
| Shinji Okazaki | 16 Apr 1986 | 2015-16 – 2018-19 | Leicester City | 9 | 2 |
| Liam O'Kane | 17 Jun 1948 | 1969-70 – 1971-72 | Nottingham Forest | 5 | 0 |
| Eunan O'Kane | 10 Jul 1990 | 2013-14 – 2016-17 | Bournemouth, Leeds United | 4 | 0 |
| Stefano Okaka | 9 Aug 1989 | 2009-10 – 2017-18 | Watford, Fulham | 4 | 1 |
| Noah Okafor | 24 May 2000 | 2024-25 – 2025-26 | Leeds United, AC Milan | 3 | 0 |
| Juhani Ojala | 19 Jun 1989 | 2012-13 | Young Boys | 2 | 1 |
| Jörgen Ohlin | 19 Dec 1937 | 1967-68 | Malmo | 1 | 0 |
| John O'Hare | 24 Sept 1946 | 1966-67 – 1979-80 | Derby County, Nottingham Forest, Sunderland | 14 | 6 |
| John O'Hare | 1936-37 – 1938-39 | Chelsea | 3 | 0 | |
| Mike O'Hara | 30 Aug 1944 | 1960-61 | Luton Town | 2 | 0 |
| Jamie O'Hara | 25 Sept 1986 | 2007-08 – 2011-12 | Tottenham Hotspur, Portsmouth, Wolves | 7 | 0 |
| Eddie O'Hara | 28 Oct 1935 | 1959-60 | Rotherham United | 1 | 0 |
Total: 16004 players | Page 52 of 161