- Memorial Bridge Commission1
- Merchant Marine and Fisheries Committee378
- Merchant Marine and Fisheries Committee, House1,057
- Merchant Marine and Fisheries Committee, Senate1
- Merchant Marine, Radio, and Fisheries Committee, House54
- Migratory Bird Conservation Commission11
- Military Affairs Committee3,034
- Military Affairs Committee, House2,707
- Military Affairs Committee, Senate2,232
- Militia Committee6
- Mines and Mining Committee112
- Mines and Mining Committee, House59
- Mines and Mining Committee, Senate65
- Minks and Mining Committee2
- Missing Persons in Southeast Asia, Select Committee on, House2
- Munitions Industry, Special Committee Investigating, Senate26
- Muscle Shoals Joint Committee5
- National Botanic Garden15
- National Botanic Garden Library Joint Committee1
- National Defense Migration, Select Committee Investigating, House19