The 2012–13 Football League Championship was the 128th season in the history of Millwall Football Club. It was their 87th season as a Football League side and their 38th in the second tier of English football. This season marked Millwall's third continuous season in the Championship, after promotion from League One in 2010. This was manager Kenny Jackett's fifth and final season in charge of the club, he resigned at the end of the campaign on 7 May 2013.