Wolverhampton, Staffordshire born inside left Billy Bagley played junior football for Newport Excelsior from 1928 and from there joined Third Division (South) Newport County in 1929, making his Football League debut against Brentford in February 1930. He established himself in the Newport line up the next season and he was bought by First Division Portsmouth in June 1933 after 13 goals in 75 appearances. Initially a fringe player, in his first season at Fratton Park he played in 4 earlier round Cup ties up to the Fifth Round, scoring in a Third Round 1-1 draw at Manchester United, as Portsmouth went on to the 1934 FA Cup Final, where they lost to Manchester City.
Bagley only established a regular place in the Pompey line up in 1935-36. But he lost his place in 1937 and became a fringe player (he didn’t play in Portsmouth’s 1939 FA Cup Final victory) until the outbreak of the Second World War in September 1939, which effectively ended his football career by when he had scored 13 goals in 139 appearances for Pompey.