[citation needed] The Nationals won the J. Ross Robertson Cup as champions of the OHA in 1930, and defeated the Niagara Falls Cataracts by an 11–9 combined score in two games.
[2] The Nationals were finalists for the J. Ross Robertson Cup in 1931, and were defeated by the Niagara Falls Cataracts by a 12–7 combined score in two games.
[1] The Nationals won the J. Ross Robertson Cup in 1936, by defeating the Kitchener Greenshirts in two games in a best-of-three series.
[1] The Nationals were led by Peanuts O'Flaherty, who was the league's leading scorer and winner of the Eddie Powers Memorial Trophy.
The Nationals earned a berth in the 1936 Memorial Cup played in Toronto, and defeated the Saskatoon Wesleys in two games, by scores of 5–1 and 4–2.