Ren is a diminutive of the feminine given name Renée.
Ren or REN might refer to:
- Orenburg Tsentralny Airport, IATA code REN, civil airport in Russia
- Redes Energéticas Nacionais (REN), Portuguese company
- Renanthera, abbreviated as Ren, orchid genus
- Ringer equivalence number (REN), a number which denotes the loading effect of a telephone ringer on a telephone line
- Ren County, in Hebei, China
- Ren, Iran, a village in Kerman Province, Iran
- Ren, Rajasthan, a village in Merta Tehsil of Nagaur district, Rajasthan
- Ren (Tsukihime), a character from the game Kagetsu Tohya and Melty Blood: Re-ACT
- Ren, son of Primus, protagonist of the animated series The Pirates of Dark Water
- Ren Akiyama of Kamen Rider
- Ren Gottlieb, a character from the Australian soap Neighbours
- Ren Höek, a fictional Chihuahua from the Nickelodeon animated series The Ren & Stimpy Show
- Ren Honjo, a character from the manga, anime, and film NANA
- Ren Mihashi, main character from the manga, anime and game from Big Windup!
- Ren Jinguuji, a character from the anime, game and manga from Uta no Prince-sama
- Ren Karas, a character from the anime and manga Element Hunters
- Ren Krawler, the Darkus protagonist from the animated series Bakugan: Gundalian Invaders
- Ren a character from the (yaoi)game and (not yaoi)anime "DRAMAtical Murder"
- Ren Kosaka, main character from the 2008 Japanese tokusatsu television series, Engine Sentai Go-onger
- Ren Maka, a character from the anime Chibi Vampire
- Ren McCormack, the main character from the film Footloose
- Ren Ren Ren Nagusaran Renshia Rurunnren Nakora, heroine of DearS
- Ren Sohma, the mother of Akito Sohma in the manga Fruits Basket
- Ren Stevens, a character from Even Stevens
- Ren Tsuruga, character in the manga Skip Beat
- Tao Ren (Len Tao), a character in Shaman King
- Wuying Ren, a character from Shenmue II
- Kylo Ren, a character from Star Wars Episode VII: The Force Awakens. The title (Ren) he earned or chose when he joined a group called the Knights of Ren.
- Hakuryuu Ren, Fourth Imperial Prince of Kou in the anime Magi: The Labyrinth of Magic and Magi: The Kingdom of Magic