The Mali international joins the Eagles on a five-year-deal as Patrick Vieira continues to strengthen his squad in the summer transfer window, following the arrivals of winger Malcolm Ebiowei and goalkeeper Sam Johnstone.
Doucouré played 34 times in Ligue 1 last season, guiding Lens to seventh place as a stalwart in the centre of midfield. His efforts capped a successful spell at the French side, having joined them in the second tier in 2018 and been a key part of their promotion-winning campaign.
