Internationals who have played for Carmarthen at some time during their career.
| Name | Between Years | Team |
|---|---|---|
| Josh Adams | 2018 - 2024 | Wales |
| Paul Arnold | 1990 - 1996 | Wales |
| Charlie Arthur | 1888 - 1891 | Wales |
| Dudley Bartlett | 1927 - 1928 | Wales |
| Roy Bergiers | 1972 - 1975 | Wales |
| Ronnie Boon | 1930 - 1933 | Wales |
| Aled Davies | 2017 - 2019 | Wales |
| Barry Davies | 2006 - 2006 | Wales |
| Cowboy Davies | 1956 - 1956 | Wales |
| Gareth Davies | 2014 - 2024 | Wales |
| Ivor Davies | 1914 - 1914 | Wales |
| James Davies | 2018 - 2020 | Wales |
| Mefin Davies | 2002 - 2007 | Wales |
| Dom Day | 2015 - 2015 | Wales |
| Ryan Elias | 2017 - 2024 | Wales |
| Dan Evans | 2009 - 2009 | Wales |
| Ieuan Evans | 1987 - 1998 | Wales |
| Rob Evans | 2015 - 2020 | Wales |
| Steffan Evans | 2017 - 2019 | Wales |
| Jonny Fa'amatuainu | 2005 - 2011 | Samoa |
| Ray Gravell | 1975 - 1982 | Wales |
| James Griffiths | 2000 - 2000 | Wales |
| Jonathan Griffiths | 1988 - 1989 | Wales |
| Kieran Hardy | 2020 - 2024 | Wales |
| Aisea Havili | 2000 - 2007 | Tonga |
| Adam Jones | 2006 - 2006 | Wales |
| Deiniol Jones | 2000 - 2010 | Wales |
| Mark Jones | 2001 - 2009 | Wales |
| Rhodri Jones | 2012 - 2022 | Wales |
| Stephen Jones | 1998 - 2011 | Wales |
| William Jones | 1924 - 1924 | Wales |
| Wyn Jones | 2017 - 2023 | Wales |
| Tommy Jones-Davies | 1930 - 1931 | Wales |
| Jonny Koloi | 1998 - 2001 | Tonga |
| ALP Lewis | 1996 - 2002 | Wales |
| Percy Lloyd | 1890 - 1891 | Wales |
| Sililo Martens | 1998 - 2009 | Tonga |
| Kemsley Mathias | 2023 - 2024 | Wales |
| Robin McBryde | 1994 - 2005 | Wales |
| Rob McCusker | 2010 - 2013 | Wales |
| Ronnie Morris | 1933 - 1937 | Wales |
| Kirby Myhill | 2021 - 2021 | Wales |
| William Norton | 1882 - 1884 | Wales |
| Harri O'Connor | 2024 - 2024 | Wales |
| Ken Owens | 2011 - 2023 | Wales |
| Kevin Phillips | 1987 - 1991 | Wales |
| Tom Price-Jenkins | 1888 - 1888 | Wales |
| Rhys Priestland | 2011 - 2022 | Wales |
| Tom Prydie | 2010 - 2018 | Wales |
| Richie Pugh | 2005 - 2005 | Wales |
| Matthew Rees | 2005 - 2014 | Wales |
| Richard Rees | 1998 - 1998 | Wales |
| Harry Robinson | 2012 - 2013 | Wales |
| Javan Sebastian | 2021 - 2024 | Scotland |
| Tal Selley | 2005 - 2005 | Wales |
| Michael Tagicakibau | 2007 - 2011 | Fiji |
| John Thiel | 1998 - 2008 | Canada |
| Arwel Thomas | 1996 - 2000 | Wales |
| Delme Thomas | 1966 - 1974 | Wales |
| Gareth Thomas | 2021 - 2024 | Wales |
| Rhys Thomas | 2006 - 2009 | Wales |
| Rowley Thomas | 1889 - 1892 | Wales |
| Sione Timani | 2008 - 2012 | Tonga |
| Josh Turnbull | 2011 - 2021 | Wales |
| Adam Warren | 2012 - 2012 | Wales |
| Dave Watt | 1967 - 1967 | England |
| Scott Williams | 2011 - 2019 | Wales |
Jonathan Griffiths was a dual code international – played for Wales in Rugby League.