He moved to English club Leicester City on 11 January 2014, signing a three-and-a-half-year contract. Mahrez made his debut on 25 January 2014, coming on in the 79th minute as a substitute replacing fellow winger Lloyd Dyer. After making four substitute appearances for Leicester, including scoring his first goal for the club, manager Nigel Pearson announced in February 2014 that he thought Mahrez was ready to start games.
In November 2013 Mahrez expressed his desire to represent Algeria internationally. He was called up to the provisional Algerian squad for the 2014 FIFA World Cup. On 31 May 2014, Mahrez made his international debut for the Desert Foxes as a starter in a pre-World Cup friendly match against Armenia, and he was subsequently called up to the full-squad for the tournament on 2 June.