The following are known Action Replay Codes for Mario Tennis on Nintendo 64 (N64).

Device Compatibility: Action Replay & GameShark

Msater Code – Must Be On
f13002903c01
f1300292a005
f130029803e0
f130029A0008
f130029cac20
f130029e86a0

Press C-Down for 1 Point Win P1
d00669850004
8015344a0003

Press C-Down for 1 Point Win P2
d00669850004
8015344b0003

Press C-Down for P1 Scores 0
d00669850004
8015344a0003

Press C-Down for P2 Scores 0
d00669850004
8015344b0000

Press C-Down For Easy Win Ring Shot
d00669850004
801535270069
d00669850004
801535230069

Instant Paranha Challenge Win
8115137e0032
811513820032