The 1988–89 Campionato Sammarinese di Calcio season was the 4th season since its establishment. It was contested by 10 teams, and S.P. Domagnano won the championship defeating S.P. La Fiorita 2-1 in the finals.
Regular season
Championship playoff
First round S.C. Faetano 0-0 (pen 4-3) F.C. Domagnano S.S. Murata 2-0 S.P. Cailungo
Second round F.C. Domagnano 0-0 (pen 4-2) S.S. Murata S.C. Faetano 4-1 S.P. Cailungo
Third round F.C. Domagnano 2-0 S.S. Murata S.P. La Fiorita 0-0 (pen 5-4) S.C. Faetano
Fourth round F.C. Domagnano 1-0 S.C. Faetano S.P. La Fiorita 1-0 A.C. Libertas
Semifinal A.C. Libertas 0-1 F.C. Domagnano
Final F.C. Domagnano 2-1 S.P. La Fiorita
References San Marino - List of final tables (RSSSF)