Mountford was born in Kidderminster and began his career playing for local side Kidderminster Harriers before joining Stoke City in December 1942 for a fee of £40. During the War League Mountford established himself in Bob McGrory's side as a right winger providing crosses for Tommy Sale and namesake Frank Mountford. With Stanley Matthews on wartime duty with Blackpool Mountford took his number 7 shirt and Matthews struggled to win it back. Whilst he was not as talented as Matthews, Mountford made up for it with his hard work and possessed a good turn of speed which often took him into goalscoring opportunities. Throughout the 1946–47 season Matthews and Mountford both vied for the right wing position and when Matthews suffered an injury early in the campaign Mountford took his place. Even when Matthews had recovered McGrory stuck with Mountford as Stoke pushed for the First Division title. The Unhappy Matthews left for Blackpool in May 1947 and Mountford scored a vital goal against Aston Villa to take the title race in to the final day of the season. Stoke needed to beat Sheffield United to claim the title but they lost 2–1 and the chance had gone. The side struggled with injuries in 1947–48 and Mountford made 29 appearances scoring five goals. He scored a career best of 11 in 1948–49 as Stoke finished in 11th position. In 1949–50 he played 32 times scoring six goals as the Potters narrowly avoided relegation. At the end of the 1949–50 season Mountford was convinced to join Colombian side Independiente Santa Fe along with Stoke teammate Neil Franklin, the move caused outrage with the FA as Colombia at the time was not a FIFA member. Mountford spent the who season in Colombia where he became a favourite with the Independiente support who dubbed him the "Bald Arrow". He returned to Stoke in the summer of 1951 and he found himself both suspended by Stoke and the Football League. His suspension was lifted in September 1951 and he resumed playing in the Stoke team. In October 1953 Mountford was sold to Queens Park Rangers in exchange for Des Farrow. In September 1953 Mountford returned to his roots playing for Hereford United, Kidderminster Harriers and Lockheed Leamington.
