The 2015–16 season was Millwall's 131st year in existence and their first back in League One since the 2009–10 season, after being relegated from The Championship the previous season. It was Millwall's 90th consecutive season in The Football League and 42nd in the third tier. Along with competing in League One, the club participated in the FA Cup, League Cup and Football League Trophy. The season marked the first full season in charge for club record goalscorer Neil Harris, who became manager in April. He led the club to fourth place, finishing with 81 points and a play-off place. This season covers the period from 1 July 2015 to 30 June 2016.
On 5 May 2015, Millwall announced a pre-season friendly with AFC Wimbledon to take place on 18 July 2015.[27] On 29 May 2015, Millwall added Stevenage to their pre-season schedule.[28] On 1 June 2015, the club announced a friendly against Bromley.[29] On 10 June 2015, Millwall announced they will host Portuguese side Tondela on 1 August 2015.[30]
Updated to match(es) played on 1 July 2016. Source: BBC Sport Rules for classification: 1) Points; 2) Goal difference; 3) Number of goals scored (O) Play-off winners; (P) Promoted Notes: