Ickleford, near Hitchin, Hertfordshire born outside right Billy Grimes began his football career with Hitchin St John’s and played for Hitchin Town in 1905, from where he was signed by Southern League club Watford in 1906. He was then signed by Second Division club Glossop in May 1907, making his Football League debut at Grimsby Town that September. In a year and a half with The Hillmen he impressed enough for First Division club Bradford City to step in for his signature in December 1908 after 10 goals in 48 appearances for Glossop, Grimes scoring on his top flight debut for The Bantams days after signing in a 4-1 win over Woolwich Arsenal at Valley Parade, his only goal for Bradford in 16 matches that season.
But he was largely overlooked during 1909-10 and after only two first team matches he signed for Second Division club Derby County in March 1910. Having established himself as a first team regular from October 1910, Grimes missed only 3 matches as The Rams won the Second Division Championship in 1911-12, and remained a regular in their First Division line up, although they again suffered relegation in 1914. He then helped Derby to once again win the Second Division Championship in 1914-15, however his career was severely interrupted by the onset of the First World War, which forced the suspension of peacetime football in May 1915, by when Grimes had scored 11 goals in 169 matches for Derby County. After the War was over he joined Southern League club Luton Town for a season in 1919-20 but had retired by the time The Hatters joined The Football League in the summer of 1920.
Grimes was married to Ameila Furr, sister of the footballing brothers George, Harry, Vic and Willie Furr. He played with George Furr while at Watford and Willie Furr while at Luton Town.