YM, Ym, or ym may refer to:
- YM (magazine), an American teen magazine
- YM (selective medium), a selective growth medium which is a combination of yeast and mold
- .ym, the Atari ST/Amstrad CPC YM2149 sound chip format
- YM, the US Navy Hull classification symbol for a self-propelled dredge
- Montenegro Airlines IATA airport code
- Yahoo! Mail
- Yahoo! Mash
- Yahoo! Maps
- Yahoo! Messenger, an instant messaging application
- Yahoo! Mobile
- Yahoo! Movies
- Yahoo! Music
- Yarmouth Mariners, a Maritime Junior A Hockey League team
- Yngwie J. Malmsteen, a Swedish Guitarist
- "Ynnä muuta", a Finnish phrase meaning roughly "and the others" or "etc."
- Yokozuna Monogatari, a 1994 Japanese sumo wrestling video game
- Yottametre, a unit for length or distance
- Youth Meeting, a program of CISV International
YM was an American teen magazine that began in 1932. The magazine ceased publication in 2004.
YM Agar and Broth, is a selective growth medium with low pH useful for cultivating yeasts, molds, or other acid-tolerant or acidophilic organisms, while deterring growth of most bacteria and other acid intolerant organisms. It is Malt extract medium modified by the addition of Yeast extract and peptone.
The 'YM' of the name stands either for 'Yeast and Mold', or 'Yeast extract-Malt extract' depending on the source.