Fulham have signed Zambo Anguissa in a £22.3m deal, one of five transfers the Cottagers completed on Thursday.
Bristol City left-back Joe Bryan joined for £6m, with loan deals for Atletico Madrid forward Luciano Vietto, Sevilla goalkeeper Sergio Rico and Manchester United defender Timothy Fosu-Mensah.
It means Fulham have been the busiest club on transfer deadline day.
Zambo Anguissa’s deal is the Cottagers’ 12th signing of the summer.
The 22-year-old is a Cameroon international and played 54 times in all competitions for Marseille last season, including the Europa League final, where the French club lost 3-0 to Atletico Madrid.
“I’m delighted to have signed for Fulham,” said Zambo Anguissa, who has signed a five-year contract. “This is a new chapter in my career and one I’m really looking forward to.
“I hope to bring my qualities to this new project. I like a challenge and I will give my very best to my team, the club and the supporters.”
Fosu-Mensah, 20, has represented the Netherlands at senior level, Rico, 24, has played once for Spain and won the Europa League with Sevilla in 2015 and 24-year-old Vietto has played for Argentina’s Under-20s.
Bryan made 48 appearances in all competitions last season for Bristol City and played in their 2018-19 Championship opener, a 2-2 draw with Nottingham Forest last Saturday.
The 24-year-old was close to joining Aston Villa on Wednesday, but has opted to join Premier League newcomers Fulham. He said: “The opportunity to play in the Premier League is one you can’t turn down as you may never get it again in your lifetime.
“I’m used to playing fast attacking football, so hopefully I can slot right in.”