| Club: | Millwall |
| Season: | 1988–89 |
| Manager: | John Docherty |
| Chairman: | Reg Burr |
| Stadium: | The Den |
| League: | First Division |
| League Result: | 10th |
| Cup1: | FA Cup |
| Cup1 Result: | Fourth round |
| Cup2: | League Cup |
| Cup2 Result: | Third round |
| Cup3: | Full Members Cup |
| Cup3 Result: | Third round |
| League Topscorer: | Tony Cascarino (13) |
| Season Topscorer: | Teddy Sheringham (15) Tony Cascarino (15) |
| Highest Attendance: | 22,103 (vs. Liverpool) |
| Lowest Attendance: | 11,394 (vs. Middlesbrough) |
| Average Attendance: | 15,468 |
| Prevseason: | 1987–88 |
| Nextseason: | 1989–90 |
During the 1988–89 English football season, Millwall F.C. competed in the Football League First Division. This was Millwall's 62nd season in the Football League, and first ever season in the top tier of English football, after achieving promotion from the Second Division as Champions in 1987–88.
Millwall had won promotion to the First Division for the first time in their history as Second Division champions at the end of the 1987–88 season, and were among the pre-season favourites for relegation, but defied the odds and were top of the First Division by the beginning of October, having won four of their first six league games. By Christmas, they were still an impressive fifth in the league, but finished 10th at the end of the season after failing to win any of their final 10 games. Perhaps the only low point of the season was being defeated by arch-rivals West Ham United twice during the season, although Millwall still outperformed their local rivals for the first time in decades, as the Hammers were relegated in 19th place.
Millwall finished one place above Manchester United, one of the pre-season title favourites, and spent much of the season in a higher position than other teams who failed to emerge as title contenders after being among the pre-season favourites, including Everton and Tottenham Hotspur – who both eventually finished slightly above Millwall.
Millwall's high placing owed much to the strike partnership of Teddy Sheringham and Tony Cascarino.
In his autobiography, Sheringham said of the season, "It was a crazy exhilarating time. There we were, little Millwall, in our first season in the First Division and topping the table until about March. Everybody said it couldn't last and of course it couldn't and it didn't, but we gave them all a good run for their money. We were beating the best teams when we shouldn't and getting away draws to which we had no right."
http://www.millwall-history.org.uk/Millwall-Stats8889-2.htm