Tri County Baseball League was an Independent League that was based in Ontario, Canada.
1923 Newmarket, Stouffville, Sutton, Uxbridge
1924-1948 Unknown if played.
1949 Beaverton, Bolsover, Port Perry Stouffville, Sunderland, Sutton
1950 - Port Perry, Stouffville (only teams found).
1951-1953 Unknown if played.
1954 Bobcaygeon, Lindsay, Port Perry, Stouffville, Sunderland, Sutton
1955 Lindsay, Newmarket, Port Perry, Stouffville, Sunderland
1955 Newmarket, Orillia, Port Perry, Stouffville, Sunderland
1956 Newmarket, Orillia, Port Perry, Stouffville, Sunderland