Gordon Douglas Slade FRS FRSC (born December 14, 1955, in Toronto) is a Canadian mathematician, specializing in probability theory.^[1][2]

Slade received in 1977 his bachelor's degree from the University of Toronto and in 1984 his PhD for research supervised by Joel Feldman and Lon Rosen at the University of British Columbia.^[3]

As a postdoc he was a lecturer at the University of Virginia. From 1986 he was at McMaster University and since 1999 he is a professor at the University of British Columbia.

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. The Hara–Slade result has important consequences in mean field theory.^[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]