Celtic completed a second successive domestic treble after beating Motherwell 2-0 in the Scottish Cup final on Saturday.
Callum McGregor put Celtic ahead in the 11th minute and Olivier Ntcham netted in the 25th with a 25-yard drive at Hampden Park.
Brendan Rodgers' side had already won a seventh straight Scottish Premiership and a second successive League Cup, confirming the Glasgow club's complete dominance in the country.