Plymouth Argyle Born in
Plympton, England He progressed through the club's Centre of Excellence to be rewarded with a two-year apprenticeship at the end of the
2007–08. Regarded as one for the future. His elevation to training regularly with the club's first-team coincided with the return of former player
Paul Mariner to Plymouth Argyle and, despite still being an apprentice, he made his first-team debut for the club on 27 March 2010 against
Blackpool at
Home Park.
Loans to Weston-super-Mare and Tiverton Town Leonard joined
Weston-super-Mare on loan in December 2010, where he made five appearances in the
Conference South. In January 2011, he joined
Tiverton Town on loan for one month, which was then extended until the end of April.
Return to Plymouth Argyle Leonard was released by Plymouth Argyle at the end of the 2010–11 season.
Southend United in 2014. Leonard signed a one-year deal with
Southend United on 27 July 2011, with the option of a further year after impressing on trial. Leonard scored three goals during Southend's pre-season, including one from inside his own half. On 7 March 2014, Leonard signed a new three-and-a-half-year contract extension with Southend. At the end of the
2014–15 season he played for Southend in the
League Two play-off final against
Wycombe Wanderers. Leonard also scooped awards for Players' Player and Goal of the Season.
Sheffield United On 5 January 2018, Southend announced that terms had been agreed with
Championship club
Sheffield United for Leonard's transfer. Leonard agreed terms with the Blades on 6 January, and it was reported he would join them subject to completing a medical. Leonard signed for Sheffield United on 9 January 2018 and was unveiled as a player on the same day.
Millwall On 31 August 2018, Leonard signed for Millwall initially on loan, but the deal became permanent in January for a club record fee of £1.5 million. ==Personal life==