Sunderland born centre forward Harry Leonard began his football career with Wearside League club Sunderland West End and played for Southwick before being signed by First Division club Newcastle United in November 1907, spending the rest of 1907-08 at St James’ Park without making a first team appearance, during which time he also returned on loan to play for Sunderland West End. In May 1908 Leonard signed for Second Division club Grimsby Town, making his Football League debut at Birmingham that September, initially playing mostly at inside forward both sides before making the centre forward position his own.
Between February and April 1910 he scored 13 goals in 10 matches including two hat-tricks in wins over Glossop and Burnley, finishing as comfortably The Mariners’ leading goalscorer, however when they were not re-elected and lost their League status, he continued to star for Grimsby’s team that won the 1910-11 Midland League Championship, but before the season end he was signed by First Division club Middlesbrough in late March 1911 after 23 goals in 53 appearances during his two League seasons at Blundell Park. His spell at Ayresome Park was brief and he signed for Second Division Derby County the same October after 3 goals in 13 matches for ‘Boro.
His contribution to Derby’s success was immediate, scoring 4 goals in his third match in a win over Fulham and another hat-trick in a win over Gainsborough Trinity in April 1912, with 18 goals overall as The Rams win the Second Division Championship, Leonard only finishing behind the great Steve Bloomer in their goalscoring list. He scored a further 15 goals as Derby finished seventh in the League Championship in 1912-13, and despite their relegation in 1914, he again spearheaded Derby to the Second Division Championship in 1914-15 with a career best 19 goals in 32 appearances, his total only bettered by ever present Jim Moore.
However the onset of the First World War forced the suspension of peacetime football, and during the War Leonard served in The Royal Engineers, but after the War he returned to The Baseball Ground and scored a dozen goals in Derby’s 1919-20 campaign, joint top scoring with Noah Burton as Derby struggled towards the bottom of the table. Already aged 34, he was then signed by Manchester United in September 1920 after 73 goals in 150 appearances for Derby County, going straight into the team and scoring three times in his first two matches for The Red Devils in home and away wins over Chelsea. However he lost his place in the first team in December and played just once more for United before joining non league Heanor Town in September 1921 after 5 goals in 10 appearances, his final club before his eventual retirement.