The 1998–99 SPL season was one that ended in success for Rangers. Dutchman Dick Advocaat was brought in to replace Walter Smith at Rangers and made major changes, bringing in many players.
Rangers were comfortable for most of the season, being top for most of it. Their main low of the season was a 5–1 defeat to Celtic at Parkhead. After beating Aberdeen 3–1 at Ibrox on 25 April, Rangers had a chance to clinch the title at Parkhead on 2 May. Rangers did what they wanted to do with a 3–0 victory. 2 goals from Neil McCann and a Jorg Albertzpenalty gave Rangers their 100th league victory over Celtic. The match was overshadowed by the controversy during and after the game. 3 players were sent off and referee Hugh Dallas was hit by a coin thrown from the Celtic end.
Rangers won the Scottish domestic treble in their first season under the management of Dick Advocaat.
Following the resignation of manager Wim Jansen, Celtic appointed 62-year-old former Aston Villa and Czechoslovakia manager Jozef Venglos as his successor. However, the appointment was not a success as Celtic finished the season without a major trophy and Venglos departed to be succeeded by the new management team of director of football Kenny Dalglish and head coach John Barnes.
Paul Sturrock departed St Johnstone at the start of the season to take over at Dundee United.
New St Johnstone manager Sandy Clark guided St Johnstone to the club's best ever finish of third in the SPL, earning UEFA Cup qualification for only the second time. The Saints also reached the final of the League Cup and the semi-finals of the Scottish Cup.
Hibernian returned to the top flight at the first time of asking as Division One champions.
28-year-old Rangers defender Alan McLaren, who was capped 24 times for Scotland between 1992 and 1995, retired at the end of the season after two years out of action due to injury.
Rod Wallace, who was part of the Leeds United team that won the English league title in 1992, joined Rangers at the start of the season and added the Scottish title and both domestic cups to his list of honours.
After 11 years in England with Manchester United, veteran striker Brian McClair rejoined his old club Motherwell but played just 11 games for them before moving back south of the border in December to become assistant manager to former Manchester United coach Brian Kidd at Blackburn Rovers. Ironically, McClair was initially reported to be leaving Scotland for the Manchester United assistant manager's job left vacant by Kidd's move to Blackburn.