Wilhelm Friedrich Ackermann (/ˈækərmən/; German: [ˈakɐˌman]; 29 March 1896 – 24 December 1962) was a German mathematician and logician best known for his work in mathematical logic[1] and the Ackermann function, an important example in the theory of computation.

Ackermann was born in Herscheid, Germany, and was awarded a Ph.D. by the University of Göttingen in 1925 for his thesis Begründung des "tertium non datur" mittels der Hilbertschen Theorie der Widerspruchsfreiheit, which was a consistency proof of arithmetic apparently without Peano induction (although it did use e.g. induction over the length of proofs).

He was also a corresponding member of the Akademie der Wissenschaften (Academy of Sciences) in Göttingen, and was an honorary professor at the University of Münster.

This text contained the first exposition ever of first-order logic, and posed the problem of its completeness and decidability (Entscheidungsproblem).

He kept engaged in the field of research and published many contributions to the foundations of mathematics until the end of his life.