Gordon Douglas Slade (born December 14, 1955, in Toronto) is a Canadian mathematician, specializing in probability theory.

He developed the technique of lace expansion (originally introduced by David Brydges and Thomas C. Spencer in 1985) with applications to probability theory and statistical mechanics, such as self-avoiding random walks and their enumeration, random graphs, percolation theory, and branched polymers.

In 1989 Slade proved with Takashi Hara that the Aizenman–Newman triangle condition at critical percolation is valid in sufficiently high dimension.

[4] In 1991 Slade and Hara used the lace expansion to prove that the average distance covered in self-avoiding random walks in 5 or more dimension grows as the square root of the number of steps and that the scaling limit is Brownian motion.

[5] Slade was an invited speaker in 1994 at the ICM in Zürich with lecture The critical behaviour of random systems.