Extremism, ideas or actions beyond what is deemed acceptable

Extreme, an autobiography by Sharon Osbourne

Dance Dance Revolution EXTREME

Extreme Programming, also known as XP

Extremophile, an organism which thrives in or requires "extreme" conditions

Extreme (band), an American band, mostly known for its ballad "More than Words"

Adam X the X-Treme, a Marvel Comics character also known as Adam X or Adam Neramani

Xtreme Pro Wrestling

Extreme sport, featuring speed, height, danger or spectacular stunts

Extreme Associates, a pornographic video and DVD company

Extreme weather, severe or unseasonal weather

Extremes, a television series

Extreme Sports Channel, a Netherlands-based extreme sports television channel available across Europe and the Middle East

Extreme value, the largest and the smallest element of a set

Extreme Paintbrawl, a budget first person shooter that is considered one of the worst games ever

Agostino Carollo, an Italian singer, disc jockey, and producer, better known as "X-Treme"

Xtreme (group), a Latin music group

Extreme Networks, a California based enterprise level networking hardware company

Extreme (marketing), the term as used in advertising and marketing

Extreme Records, a record label

Extremes (album), a 1994 album by Collin Raye

Extreme Championship Wrestling, the former independent promotion that now operates as a brand for World Wrestling Entertainment.