Stéphane Georges Mallat (born 24 October 1962) is a French applied mathematician, concurrently appointed as Professor at Collège de France and École normale supérieure.

He has additionally done work in applied mathematics, signal processing, music synthesis and image segmentation.

With Yves Meyer, he developed the multiresolution analysis (MRA) construction for compactly supported wavelets.

Mallat is the author of A Wavelet Tour of Signal Processing (1999; ISBN 012466606X), a text widely used in applied mathematics and engineering courses.

He has held teaching positions at New York University, Massachusetts Institute of Technology, École polytechnique and at the Ecole normale supérieure.