Alf Common was born on 25 May 1880 at his parents' home, 27 North Milburn Street, Sunderland, the son of Robert Ridley Common, a riveter, and his wife, Sarah Ann Towers. He played for South Hilton juniors and Jarrow before signing for his home town team in 1897 as a goalscoring centre forward or outside right. In November 1901, not long after he had broken into the Sunderland first team, he was transferred to Sheffield United for a fee of £325. He played a vital part in Sheffield United's run to the cup final of 1902, in which he scored in the first game and made the pass for the winning goal in the replay. There is some suggestion that homesickness led to his return to Sunderland in 1904 for £520.

Common will always be remembered for the fact that he was the first footballer to cost £1000. That was the sum which Middlesbrough paid Sunderland to take him to Teesside in February 1905. Some members of the Football Association (FA), most notably J. C. Clegg, had long believed that the practice of ‘buying and selling players is unsportsmanlike and most objectionable in itself, and ought not to be entertained by those who desire to see the game played under proper conditions'. Common's transfer provoked an attempt to bring the market for players under some control, and the FA actually made a rule, to come into effect from 1 January 1908, that no club should be entitled to pay or receive any transfer fee, or other payment exceeding £350 upon or in respect of the transfer of any player. It lasted for three months. It was so obviously being ignored by the clubs that it had to be withdrawn.

The signing of Common was part of a last-ditch strategy to save Middlesbrough from relegation and Common's goals helped to do the trick. He was also appointed club captain. The club was later to be convicted by the FA of paying illegal bonuses to players during their successful cup run in 1904 and the relegation battle of 1905. None of the players was suspended but eleven out of the twelve directors were.

Common appeared twice for England while at Sheffield United, scoring two goals. He was also selected to play centre forward against Wales in 1906 while a Middlesbrough player. It was at Middlesbrough that he played for a time with Steve Bloomer. Common was an aggressive and robust forward with an eye for goal. At 5 feet 8 inches and 13 stone he was a tough proposition in the penalty area, and scored 65 goals for Middlesbrough in 178 appearances.  In 1910 he moved south to Woolwich Arsenal, this time on a free transfer because Middlesbrough had no money to pay the £250 benefit which he had been promised at the beginning of that season. By then he was probably past his best and was certainly troubled by weight problems.          In December 1912 he was transferred to Preston and was a member of the team which won the second division championship in 1913.

Common left football in 1914 and returned to the north-east to become a licensee in Darlington, first at the Cleaver Hotel in Skinnergate and then spending eighteen years at the Alma Hotel, Cockerston, until his retirement in 1943. He was something of a local celebrity, in part owing to a combination of his sporting exploits and his jovial and loquacious character. His ruddy face seemed straight out of a Christmas pantomime. He died eleven months after his wife, on 3 April 1946 at his home, 326 Coniscliffe Road, Darlington.