Florian Grégoire Claude Lejeune (born 20 May 1991) is a French professional footballer who plays as a centre-back for Spanish La Liga club Rayo Vallecano.

Towards the end of the campaign, he was called up to the senior team and made his amateur debut on 11 April 2009 appearing as a substitute in a 3–1 defeat to Gazélec Ajaccio.

[5] Lejeune arrived at the club playing primarily in the defensive midfielder role, but ultimately switched to the centre back position.

[3] His positive play during the fall season with the reserves led to the player being called up to the senior team in January 2010.

On 4 January 2011, French newspaper L'Equipe announced that Spanish club Real Madrid was monitoring Lejeune's progress.

[15] On 7 July 2011, French newspaper L'Equipe confirmed that Lejeune had reached an agreement with Spanish club Villarreal to sign a four-year contract.

[16] The transfer fee was priced at €1 million and Lejeune took his medical and signed his contract following the conclusion of his participation in the 2011 FIFA U-20 World Cup.

[27] Roughly one year later, Rayo announced his permanent signing on a four-year deal,[28] for a reported fee of €2.5 million.