César Jasib Montes Castro (born 24 February 1997) is a Mexican professional footballer who plays as a centre-back for Russian Premier League club Lokomotiv Moscow and the Mexico national team.

[13] On 27 December 2022, Montes moved abroad and joined La Liga club RCD Espanyol, with a contract until 2028.

[16] On 12 September 2024, Montes signed for Russian Premier League club Lokomotiv Moscow on a five-year deal.

[20] On 7 July 2016, Montes was named by Raúl Gutiérrez to be included in Mexico's 21-man squad that would participate in the 2016 Summer Olympics in Rio de Janeiro, Brazil.

[24] He would make his debut on 13 July 2017 during a group stage match against Jamaica, coming in as a substitute for Rodolfo Pizarro at half-time, finishing the game at 0–0.

[25] On 6 June 2019, Montes was called up by coach Gerardo Martino to participate in the CONCACAF Gold Cup.

[27] In October 2022, Montes was named in Mexico's preliminary 31-man squad for the 2022 FIFA World Cup, and in November, he was ultimately included in the final 26-man roster.