The club is the most successful in the history of world rugby league, winning 22 league championships (four in the Super League era), the Challenge Cup 20 times (including eight consecutive wins between 1988 and 1995) the World Club Challenge four times and over 100 honours in total. The club has also only been relegated once in its history (in 1979–80).
^ abFrom 1906 until 1973 (except for two seasons between 1962 and 1964) a play-off format was used to determine the overall league champions. Between 1973 and 1997, the championship was awarded to the league winners, and the play-offs were replaced by the Rugby League Premiership. A play-off system for the championship was reinstated in 1998.
^ abWigan won the South West Lancashire League this season.
^ abcdThe Rugby League Championship and all cup competitions were suspended between 1915 and 1919 due to the First World War. Wigan continued to compete in a Wartime Emergency League during this period.
^The Emergency League was abandoned following the conclusion of the First World War, and was replaced by a shortened competitive season.
^Season abandoned following the outbreak of the Second World War. All results from this season have been expunged from official records.
^ abcdefThe Rugby League Championship was suspended between 1939 and 1945 due to the Second World War. Wigan continued to compete in a Wartime Emergency League during this period.
^ abcdeFollowing the suspension of the Lancashire Cup competition in 1940, Wigan competed in the Yorkshire Cup until the end of the Second World War.
^Although Wigan won their first round tie against Rochdale Hornets, the match was later awarded to Rochdale due to Wigan fielding an ineligible player.