Lyon has completed the signing of Jeff Reine-Adelaide from Angers for an initial fee of €25million.
The 21-year-old signed a five-year contract after passing a medical on Wednesday.
Angers could be due a further €2.5m in incentives and will receive 15 per cent of any capital gain from a future transfer.
"Olympique Lyonnais welcomes Jeff Reine-Adelaide, considered one of the big hopes of the future in his position," the Ligue 1 club said.
The France under-21 international joined Angers on a permanent deal last year after impressing in a loan spell away from Arsenal.
The Gunners are said to have had the opportunity to hijack the transfer to Lyon by submitting an equivalent bid.
He made 35 Ligue 1 appearances last season and scored last Saturday in the 3-1 opening-day win over Bordeaux.