Hellmuth Kneser (16 April 1898 – 23 August 1973) was a German mathematician who made notable contributions to group theory and topology.

His proof originated the concept of normal surface, a fundamental cornerstone of the theory of 3-manifolds.

He was born in Dorpat, Russian Empire (now Tartu, Estonia) and died in Tübingen, Germany.

He was an editor of Mathematische Zeitschrift, Archiv der Mathematik and Aequationes Mathematicae.

[2] In July 1934 he wrote to Ludwig Bieberbach a short note supporting his anti-semitic views and stating: "May God grant German science a unitary, powerful and continued political position.