All three teams relegated from the Sky Bet Championship in 2016/17 will re-join the second tier in 2018/19.
With Sunderland, Burton Albion and Barnsley departing for League One, Wigan Athletic, Blackburn Rovers and Rotherham United will join Millwall in The Championship next season.
millwallfc.co.uk takes a look at the trio in the second part of our 2018/19 preview...
Stadium: DW Stadium
Manager: Paul Cook
Sat Nav Post Code: WN5 0UZ
Nearest Train Station: Wigan North Western
Last Meeting: Millwall 0-0 Wigan Athletic - League One - 1st March 2016
Millwall hold the upper hand over Wigan Athletic historically, winning 12 of 29 matches since the two clubs first met in 1935. Three of the last four matches have ended in stalemate, whilst The Lions are undefeated in six against The Latics since an FA Cup Semi-Final defeat at Wembley Stadium in April 2013. Jimmy Abdou and Magaye Gueye were on target in the last victory - a 2-0 success at The Den.
Stadium: Ewood Park
Manager: Tony Mowbray
Sat Nav Post Code: BB2 4JF
Nearest Train Station: Mill Hill
Last Meeting: Blackburn Rovers 2-0 Millwall - Championship - 21st April 2015
The Lions are winless against Blackburn Rovers in five matches but can boast a famous night in the club's history over the Lancashire outfit - Danny Shittu's header securing a place in the FA Cup Semi-Finals for Kenny Jackett's side in a 1-0 Quarter-Final Replay win at Ewood Park. Meetings between Rovers and Millwall have been full of goals recently; 15 have been scored in the last four games.
Stadium: AESSEAL New York Stadium
Manager: Paul Warne
Sat Nav Post Code: S60 1AH
Nearest Train Station: Rotherham Central
Last Meeting: Rotherham United 2-1 Millwall - Championship - 28th February 2015
The Lions will be looking to gain revenge on The Millers in 2018/19 following Rotherham's double in the 2014/15 campaign. After a 1-0 early-season defeat at The Den, Martyn Woolford's goal was not enough in a 2-1 loss in Yorkshire. Millwall do hold the upper hand - just - though throughout history, having won 13 matches to The Millers' 12.