In January 1902 Hillman was transferred to Manchester City. He made his Manchester City debut on 1 February 1902 in a First Division match against Notts County at Hyde Road. He subsequently played in all 13 remaining league fixtures that season, but was unable to prevent City being relegated at the end of the season. City only spent one season in the Second Division and were promoted as champions in 1903, going on to take second place in the First Division in 1904. Hillman was also part of the Manchester City team which won the FA Cup in 1904, the club's first major trophy, remaining as first choice keeper until 1906.