Karl Willetts (born 21 September 1966) is an English death metal vocalist, best known as the lead singer of Bolt Thrower and Memoriam.

Willetts joined the British death metal band Bolt Thrower in 1988.

Willetts rejoined as a session vocalist for the recording of Mercenary and left shortly thereafter because of financial reasons and lack of commitment.

Willetts stayed in Bolt Thrower until the band broke up in 2016, following the death of drummer Martin Kearns the year before.

Willetts also did some guest vocals with UK punk band Doom on their Peel Sessions album[1] and UK death metal band Benediction on two accounts; one on "Jumping at Shadows" which appears on The Grand Leveller and Dark is the Season;[1] the other on "At the Wrong Side of the Grave", which is a cover of The Accüsed and appears on the Transcend the Rubicon album.