The 2008 edition of the Singapore Cupsoccer competition was officially known as the RHB Singapore Cup (due to sponsorship from RHB Bank). It was the 11th staging of the annual Singapore Cup tournament.
The competition began on 6 May 2008, with 12 S.League clubs and 4 invited foreign teams from Thailand (2 teams), Cambodia (1) and Brunei (1). The cup was a single-elimination tournament, with all sixteen teams playing from the first round. The first round involved one-off matches. Subsequent rounds involved ties of two legs.
The final (single-leg) was played on 28 November 2008, and SAFFC beat Woodlands Wellington 2–1, with the deciding goal scored by Kenji Arai in the first period of extra-time.