The 21-year-old left-back is a product of The Blues' Academy and has made five appearances in the EFL Trophy for the club's Under 21s since his debut in August 2022. He already has experience on loan at Sky Bet League One side Peterborough United in 2023/24, playing 15 times for The Posh across all competitions.
Millwall’s director of football Steve Gallen opened up on the deal and admitted that the club have been a fan of Sturge’s for a while.
"We've been watching Zak Sturge for a while now," said Steve Gallen, Millwall's Director of Football.
"We decided to make a move for him given the current situation. He is an athlete, is big, strong and direct and very attack-minded.
"We thank Chelsea for their assistance in getting this deal done - he is going to be a very good addition to the squad."