Professional team The Oilers were preceded in minor league play by the
Olean Refiners. Between 1908 and 1916, The Refiners played as members of the
Class D level
Interstate League. The Oilers resumed minor league play, playing in the
New York–Pennsylvania League from 1939 to 1951 and from 1955 to 1958. The league was known as the Pennsylvania–Ontario–New York League from 1939 to 1956. Their inaugural home game on May 11, 1939, was played in front of 3,300 spectators. The Oilers were a minor league affiliate of the
Brooklyn Dodgers from 1939 to 1948, the
St. Louis Browns in 1949, and the
Philadelphia Phillies from 1956 to 1958. The Oilers played their home games at
Bradner Stadium. The Oilers' president, Josephine Ross, was the only female president of an affiliated minor league team in 1959.
Collegiate summer team Starting in 2012, the Olean Oilers name has been revived as a member of the
New York Collegiate Baseball League. The team began play in the summer of 2012, initially playing on the campus of
Saint Bonaventure University before returning to a renovated Bradner Stadium in 2014; a crowd of nearly 2,000 fans watched the Oilers during their first game back at Bradner. In their fourth year of play as an amateur squad, the Oilers won the 2015 NYCBL championship; the next year, the team went on a 24-game winning streak near the beginning of the season, doubling the previous league record, en route to a league record 39 wins and a second consecutive championship, won before a league record 2,876 fans at Bradner. Despite concerns over competitive balance as well as admitted discussions with the
Perfect Game Collegiate Baseball League, the Oilers have shown a general preference to stay in the NYCBL for 2017. The Oilers eventually agreed to jump to the PCGBL in 2025. ==Year-by-year professional record==