- The Master's Men -- The Material
- The Materialistics -- The Mattaio Band
- The Matthew Herbert Big Band -- The Max Levine Ensemble
- The Max Perkoff Jazz Ensemble -- The Mayberry Movement
- The Maycocks -- The MC Club
- The McBrides -- The McCullough Kings Of Harmony
- The McCusker Bros. Ceilidhe Band -- The MCP Band
- The McPeake Family -- The Meaning Of
- The MeanStreet Riders -- The Medallions
- The Medallions -- The Meditations
- The Meditations -- The Megatons
- The Megatrons -- The Mello-Tones