CM3 may refer to:

• Championship Manager 3
• Captain Marvel Jr.
• the Chelmsford postal area
• Center for Microfibrous Materials Manufacturing
• cm³ (Cubic centimetre)
• Clay Matthews III
• Carlton Mellick III

• The Peoplepedia
• The People's Alliance (Durham, NC)
• The People's Army
• The People's Army is Loyal to the Party
• The People's Assembly Against Austerity
• The People's Car
• The People's Champ
• The People's Choice from Washington to Harding
• The People's Choice (political ticket)
• The People's College, Nottingham
• The People's College Nottingham
• The People's Court: How to Tell It to the Judge
• The People's Defence Corps of Yugoslavia
• The People's Defence Corps of Yugoslavia (KNOJ)
• The people's flag
• The people's flag is deepest red
• The People's House
• The peoples library
• The People's Orchestra
• The People's Park
• The People's Party (Samoa)
• The People's Pharmacy
• The People's Political Party
• The People's Post: A Narrative History of the Post Office
• The People's Princess