The terms PM, Pm or pm, when used by itself can refer to:

• PM is short for post meridiem (also written P.M. and pm), Latin for "after noon". This is used to disambiguate hours of the day, in the 12-hour clock system.
• PM was a politically leftist U.S. newspaper in the late 1940s and early 1950s.
• Pere Marquette Railroad
• Perry Mason
• BBC Radio 4 radio programme PM
• In electrical engineering, PM is short for phase modulation.
• The initials of Pube Muppit, a popular yet controversial Internet personality created by Flash author DrunkMagiKoopa .
• The Pope (P·M·): Pontifex Maximus
• Postmaster
• Postmortem or Post Mortem
• Preventative Maintenance
• In the government, PM is short for prime minister.
• In Internet slang, PM is short for Private Message
• In chemistry, Pm is the symbol for promethium.
• Pm is a length unit: petametre (10¹⁵ m)
• pm is a length unit: picometre (10^-12 m)
• Saint-Pierre and Miquelon: ISO 3166-1 alpha-2 country code
• The initials of Pube Muppit, a popular yet controversial Internet personality created by Flash author DrunkMagiKoopa .