George (Yuri Viktorovich) Wulff (Russian: ??????? (????) ?????????? ?????) (22 June 1863, Nizhyn (Russian Empire, nowadays Ukraine) – 25 December 1925, Moscow) was a Russian crystallographer.
The Wulff construction, Wulff net, Wulff-Bragg's condition and the mineral wulffite are named after him.
Wulff was one of the first to experiment with X-ray crystallography.