No Mercy can refer to several things:
Bands and music
No Mercy , an album by the American rap group Da Youngsta's.
No Mercy , a 1995 album by reggaeton artist Daddy Yankee.
No Mercy , a 1996 album by the pop group of the same name.
No Mercy, an album by rapper K-Rino released on 1999.
No Mercy , a 1980s thrash metal band.
No Mercy , a 1990s pop group.
No Mercy Festival, an annual heavy metal music festival in Europe.
"No Mercy", a song in the 1995 computer game Command & Conquer.
"No Mercy", a song by country singer Ty Herndon.
"No mercy", a song by L.A. Guns
"No Mercy", a song from the album Aural Sculpture by The Stranglers.
"No Mercy", a song by Nils Lofgren
Movies and entertainment
No Mercy , a movie released in 1986 starring Richard Gere and Kim Basinger
WWE No Mercy, an annual World Wrestling Entertainment event.
WWF No Mercy, a WWF video game for the Nintendo 64.
Source: http://en.wikipedia.org/wiki/No Mercy