Larmer played junior with the Kitchener Rangers. He scored over 50 goals in 1980-81 and 1981-82 and helped the team win the Memorial Cup in 1982. He was drafted 129th overall by the Colorado Rockies in the 1981 NHL Entry Draft. Larmer spent a full season with their successors, the New Jersey Devils in 1982-83, scoring 21 goals and 24 assists. The next season he was traded to the Chicago Blackhawks where he joined his younger brother Steve. Jeff could not keep a place on the Blackhawks and soon moved to Europe where he spent two seasons before retiring in 1990.