Leicester Citybus Limited, trading as First Leicester, is a bus operator providing services in Leicester. FirstGroup owns 100% of the company after purchasing Trentbarton's 6% shareholding in 2023.

In December 1874 the Leicester Tramways Company commenced operating. In July 1901 it was taken over by Leicester Corporation Transport with 39 tramcars and 30 horse-drawn buses and began to be electrified. In July 1924 the first motor buses entered service gradually replacing the trams with the last running in November 1949.

In 1972 Leicester Corporation Transit began operating services in partnership with Midland Red to South Wigston and Wigston Magna and in 1976 to Oadby. In August 1979 the business of Gibson Brothers, Barlestone was purchased which included two services from Market Bosworth to Leicester, one via Barlestone the other via Peckleton.

In 1983 Leicester Corporation Transport was rebranded as Leicester CityBus. To comply with the Transport Act 1985, in 1986 the assets of Leicester CityBus were transferred to a separate legal entity of the same name.

Leicester City Council put its 94% shareholding in Leicester CityBus up for sale in March 1993, which was purchased by the GRT Group the following November. After GRT Group merged with Badgerline to form FirstBus in April 1995, the operation was rebranded as First Leicester.

As of April 2025, the First Leicester fleet consists of approximately 100 buses, 68 of which are Wright GB Kite Electroliner battery electric single-deck buses that began entering service in May 2023; an additional 18 Streetdeck Electroliners were delivered during spring 2024. Between 2024 and 2025, 6 Wright StreetDecks new to FirstGroup between late 2015 and early 2016 entered service following conversion from diesel to battery electric by NewPower.

First Leicester's driver training fleet consists of 2 2009 Volvo B7RLEs in a yellow livery.

First Leicester also operates 5 MCV Evoras new to them in 2024 on the East Midlands Airport shuttle services.