Millwall summer transfers and net spend: Every confirmed signing and sale for Alex Neil's side in 2026 window

Millwall will look to bounce back from the bitter disappointment of missing out on automatic promotion to the Premier League and their playoff letdown with a strong summer transfer window.

Alex Neil came close to guiding the club back to the big time for the first time since relegation in the 1989-90 season, with the Lions finishing third on 84 points, one behind second-placed Ipswich Town, who secured their return to the Premier League.

Here, Sports Mole rounds up all of Millwall's confirmed ins and outs during the 2026 summer transfer window, as well as looking at their net spend and latest transfer rumours.

Millwall confirmed transfers in: Summer 2026

Elkan Baggott (CB | Undisclosed from Ipswich)

Jenson Metcalfe (CM | Undisclosed from Bradford City)

Mathis Servais (CM | Undisclosed from Mechelen)

Mark Sykes (CM | Free transfer from Bristol City)

Kyrell Lisbie (LW | Undisclosed from Peterborough United)

Danny Batth (CB | Free transfer)

Massimo Luongo (CM | Free transfer)

Jordi Osei-Tutu (RB | Free from Bolton Wanderers)

Filip Marschall (GK | Undisclosed from Stevenage)

Romain Esse (RW | Loan to Millwall)

Millwall confirmed transfers out: Summer 2026

Danny McNamara (RB | Free Agent)

Wes Harding (CB | Free transfer to Plymouth Argyle)

Joe Bryan (LB | Free Agent)

Massimo Luongo (CM | Free Agent)

Macaulay Longstaff (ST | Undisclosed to Salford City)

Barry Bannan (CM | Undisclosed to Sheffield Wednesday)

Billy Mitchell (DM | Free to Sheffield Wednesday)

Kamarl Grant (CB | loan to Bromley)

Sheldon Kendall (RW | Loan to Gillingham)

Ajay Matthews (ST |  Loan to Exeter City)

Rafiq Lamptey (CM | Loan to Chesterfield)

Femi Azeez (RW | £15m to Brighton & Hove Albion)

Millwall net spend: Summer 2026

Millwall total spend summer 2026: £0m

Millwall total income summer 2026: £15m

Millwall net spend summer 2026: £15m

When does the 2026 summer transfer window open and close?

The summer transfer window opened on Monday, June 15 for all English and Scottish clubs, and will run through to the first day of September.

This means that deadline day for the 2026 summer transfer window falls on Tuesday, September 1, with the window closing at 11pm GMT.