2017-18 ACH Season

This is the 2017-18 Allan Cup Hockey Season.  This is the league's 7th season under this name and 27th season overall. The league was previously known as Major League Hockey from 2004 to 2011, Ontario Senior AAA Hockey League from 2003 to 2004 and Southwestern Senior A Hockey League from 1990 to 2003.

Roster Changes

 * The league adopted a 17 player roster for all games which would be enough to form three lines of forwards and defencemen and have two goalies.  The press release stated it will provide first line players with more time on the ice and provide fans with a better game experience.

Membership changes

 * The Thorold Athletics are not on the league schedule when it is released on September 1, 2017.  It was later announced that the team was taking a one year leave of absence citing player challenges and stated their intent to return for 2018-19.  The team's 23 players were dispersed to the other teams in the league in a dispersal draft.
 * Due to renovations at the J. L. Grightmire Arena, the Dundas Real McCoys relocate their home games to the Harry Howell Arena in Flamborough, which was their home back in the 1970's when the team was known as the Rockton Real McCoys.

Standings
''Note a game between Whitby and Brantford originally started on February 9th that was stopped after one period due to unsafe ice conditions was rescheduled for February 25th and then cancelled on February 24th as it would have no bearing on the standings. Brantford was also dealing with large scale flooding in the community. ''

Format
The top four teams advance to the playoffs. Both rounds are best-of-seven. The playoff champion advances to the 2018 Allan Cup being held in Rosetown, Saskatchewan as the Central region representative.

Semifinals

 * Stoney Creek Generals defeated Dundas Real McCoys 4 games to none
 * Whitby Dunlops defeated Hamilton Steelhawks 4 games to 1

Final

 * Stoney Creek Generals defeated Whitby Dunlops 4 games to 1