In 1908, the club was elected into the Football League Second Division and won promotion to the First Division in their first season, and finished runners-up in their first year in the league. In 1912, Peter McWilliam became manager; Tottenham finished bottom of the league at the end of the 1914–15 season when football was suspended due to the First World War. Spurs were relegated to the Second Division on the resumption of league football after the war but quickly returned to the First Division as Second Division champions of the 1919–20 season.
On 23 April 1921, McWilliam guided Spurs to their second FA Cup win, beating Wolverhampton Wanderers 1–0 in the Cup Final. Spurs finished second to Liverpool in the league in 1922 but would finish mid-table in the next five seasons. Spurs were relegated in the 1927–28 season after McWilliam left. For most of the 1930s and 40s, Spurs languished in the Second Division, apart from a brief return to the top flight in the 1933–34 and 1934–35 seasons.