The 1917–18 Scottish football season was Celtic's 30th season of competitive football, in which they competed in the Scottish First Division.
[1] After having won the previous four championships, they narrowly failed to defend their league title as they finished runners-up just one point below Rangers.
Both teams were tied on points on the last day, but Celtic drew home to Motherwell, 1-1; and Rangers won 2-1 home against Clyde.
For the fourth consecutive season, the Scottish Cup remained suspended because of World War I, so Celtic remained title-holders.
Celtic won the Glasgow Merchants' Charity Cup for the seventh season in a row.