The club ended the season at Fratton Park with the annual Hampshire Benevolent Cup charity match against local rivals Portsmouth, which the hosts won 1–0 through a goal from Harold Buddery.

Southampton also played three friendly matches during the campaign, beating newly formed Welsh club Bridgend Town 3–1 in October, losing 1–0 to former Southern League rivals Aberdare Athletic in March, and drawing 1–1 with Third Division opponents Reading in the Berkshire Charity Cup in May.

[2] Centre-forward George Jones, another recent signing who had scored five goals in seven appearances in the club's last Southern League campaign, joined Yorkshire non-league side Goole Town.

[3] Arthur Andrews, who had established his place at right-half the previous year, was forced to retire from professional football following a broken leg in January, with Southampton releasing him at the end of the season.

[2] Later in the summer, former Saints left-half Len Butt returned to the club from Thornycrofts,[4] while Northern Irish centre-half George Moorhead joined from Sunnyside as cover for Alec Campbell.

[6] However, due to the form of Bill Rawlings, Reader's opportunities in the side were limited – after only three league appearances, he left at the end of the season to focus on a teaching career, playing part-time for Harland and Wolff.

[13] The club continued their unbeaten run until their 17th game of the season on 4 December, when they were beaten at home for the first time in almost a year at the hands of Grimsby Town, who picked up an unlikely 1–0 win after the Saints saw Tom Parker miss a penalty and James Moore sent off.

[13] Despite holding on to the top spot in the league into the new year, a winless run of four games saw the club drop below Crystal Palace, who had continued to pick up wins over the Christmas period.

[14] Losses at Northampton Town and Southend United helped Palace to extend their lead at the top of the table, with Southampton dropping down to third for a few weeks in February.

[12] Cardiff City ultimately made it to the semi-finals of the tournament for the first time in their history later that year, beating First Division side Chelsea 1–0 in the fourth round after eliminating Southampton, before being knocked out by fellow second-tier club Wolverhampton Wanderers 3–1 in a replay on 23 March.

The first was a friendly match against newly formed Welsh side Bridgend Town on 18 October 1920, which the Saints won 3–1 thanks to goals from Arthur Dominy, Fred Foxall and James Moore.

[20] The game – which drew a record crowd for the competition of 6,740 – saw the visitors forced to play right-back Tom Parker in goal in place of Tommy Allen, who had been injured, in the absence of a suitable replacement.

[20] On 14 May, a week after the last game of the league campaign, Southampton ended their season at fellow Third Division side Reading in the Berkshire Charity Cup, drawing 1–1 with a goal from Dominy.