Robert Thomas Mason (born April 22, 1961 in International Falls, Minnesota) is a retired American ice hockey goaltender.
A member of the 1984 U.S. Olympic Hockey Team, Mason's professional career began when he was signed as a free agent by the Washington Capitals. He had two stints with the Capitals (1984–87 and 1989–90). During his first stint, he was involved in one of the longest playoff games in NHL history against the New York Islanders in 1987, which took four overtimes to decide the outcome.
Mason also played for the Chicago Blackhawks (1987–88), Quebec Nordiques (1988–89), and Vancouver Canucks (1990–91).
Today, Mason is the goaltending coach for the Minnesota Wild. Previously, he was the goaltending coach for the Atlanta Thrashers during the first two years of the franchise's existence.