The 1998–99 Scottish Premier League season (also known as the 1998–99 Bank of Scotland Scottish Premier League for sponsorship reasons from 11 March) was the inaugural season of Scottish Premier League football, the top division of Scottish football. It began on 1 August 1998 and concluded on 23 May 1999. The league was made up of the twelve clubs that broke away from the Scottish Football League at the end of the 1997–98 season. Celtic went into the season as the defending Scottish champions, having won the 1997–98 Scottish Premier Division.