Underwood, Nottinghamshire born right half Billy Flint was a one club stalwart who started his football career with junior clubs Underwood & Bagthorpe in 1906 and played for Eastwood Rangers in 1907, from where he signed for First Division Notts County in 1908, making his Football League debut against Sunderland in April 1909. Originally a forward, playing all across the forward line, by November 1910 he had become a regular fixture in the first eleven and although Notts County were relegated three times during his 17 years at Meadow Lane (latterly in his final season), he was also a member of their 1914 and 1923 teams which both won The Second Division Championship. In 1913-14 he was an ever present and scored a career best 15 goals in their promotion campaign including a hat-trick at Leeds City in January 1914.
It was from November 1914 that he started playing predominantly at right half, but his career was soon interrupted by the suspension of peacetime football in May 1915 due to the onset of the First World War, during which he served in the Armed Forces. After the War he returned to Meadow Lane and made the right half berth his own for the next seven seasons, and was elected Club Captain in 1923. Such was his service that he received two benefit matches from Notts County. In total he played 408 times for Notts County scoring 41 goals, playing his last game for them in April 1926 in the season they suffered relegation from the First Division before retiring that summer already aged 36.
He also played first class cricket for Nottinghamshire between 1919 and 1929, taking 237 wickets and scoring 3,345 runs in 145 matches for the County during his cricket career.