Born in 1908 into the family of a merchant, Witt worked in the textile industry until he lost his job in June 1931.

[3] In January 1935, Witt was appointed company commander in the SS-Standarte Deutschland, a unit that later became part of the SS Division Das Reich.

On 11–12 April 1941, Witt's battalion participated in the assault on the Klidi Pass, sustaining heavy casualties in the attack.

[6] On 1 July 1943, Witt was promoted to SS-Oberführer and was appointed commander of the SS Division Hitlerjugend, the majority of its enlisted men were drawn from members of the Hitler Youth.

[10] On 7 June, members of the division under Kurt Meyer's command murdered Canadian POWs in what became known as the Ardenne Abbey massacre.

[11] When Witt learned about these crimes, he ordered an investigation and demanded a written report from Kurt Meyer.

On 14 June 1944, Witt was killed in action by a Royal Navy artillery barrage that hit the divisional command post at Venoix.