Lawrence Mysak, CM FRSC (born January 1940) is a Canadian applied mathematician, working primarily on physical oceanography, and climate research, particularly arctic and palaeoclimate research.

Lawrence continues to play the flute now with the I Medici di McGill orchestra.

Finally he joined the faculty at McGill University from 1986 until his retirement in 2010.

At McGill University Mysak was the founding director, in 1990, of the McGill Centre for Global Change Research which is now known as the Global Environment and Climate Change Centre and during his tenure Dr. Mysak served as president of the International Association for the Physical Sciences of the Oceans, IAPSO[3] and serves on the board of trustees of the Canadian Foundation for Climate and Atmospheric Sciences.

[4] Mysak's research focuses on Arctic sea ice and climate during the Little Ice Age; sea ice rheology (viscous-plastic vs. purely plastic models); modeling the freshwater budget of the Arctic Ocean and exchanges with the North Atlantic Ocean (present and past); response of the ocean carbon cycle to Milankovitch forcing in a low-order atmosphere-ocean-sea ice model; and reconstruction of climate change in Europe during the past millennium from an analysis of church architecture, comparing the Medieval Warm Period with the Little Ice Age.