Lilian Montague Brassier (born 2 November 1999) is a French professional footballer who plays as a centre-back for Ligue 1 club Rennes, on loan from Brest.

On 20 June 2019, Brassier signed a professional contract with Rennes and immediately went on loan with Valenciennes.

[3] In 2020, Brassier signed for Brest on loan with an option to buy if the club stayed up in Ligue 1.

[5] His loan deal was made permanent after Brest secured safety on the final matchday of the season.

[10] On 31 January 2025, Brassier signed for his former club Rennes on a six-month loan with a €12 million buy option.