The 2004 Football League Third Division play-off Final was an association football match which was played on 31 May 2004 at the Millennium Stadium, Cardiff, between Huddersfield Town and Mansfield Town to determine the fourth and final team to gain promotion from the Football League Third Division to Football League One. The top three teams of the 2003–04 Third Division season, Doncaster Rovers, Hull City and Torquay United, gained automatic promotion to League One, while those placed from fourth to seventh place in the table took part in play-offs. The winners of the semi-finals competed for the final place for the 2004–05 season in Football League One. Huddersfield and Mansfield defeated Lincoln City and Northampton Town, respectively, in the semi-finals.

Huddersfield Town Association Football Club is a professional association football club based in Huddersfield, West Yorkshire, England. The team competes in the EFL Championship, the second level of the English football league system. They will play in EFL League One in the 2024–25 season after suffering relegation.