Town suffered a 2-1 defeat to Scunthorpe United at The County Ground on Saturday afternoon, a loss which confirmed the club's relegation to the Sky Bet League Two.
Proceedings got off to the worse possible start for the hosts after Murray Wallace gave his side an early lead.
Jon Obika went close on a couple of occasions while Josh Morris rattled the crossbar for the visitors.
Sam Mantom doubled his side’s advantage after the break before Rohan Ince pulled one back late on, but it proved to be too little too late.
Town opted to keep faith with the same team that were narrowly beaten 1-0 by Walsall on Easter Monday.
The Reds knew that they needed a victory in order to keep alive their survival hopes but they suffered an early blow after Lawrence Vigouroux dropped a corner into the path of Murray Wallace, who was able to tuck home from close-range.
Swindon were struggling to settle into the game and they had to weather storm after storm with their guests pressing for a second goal.
Vigouroux was forced to tip Josh Morris’ 25-yard free-kick around the post, before Wallace sent an overhead kick wide and Morris fired an effort past the post.
Town were beginning to have more of the ball the longer the first-half wore on but they were being restricted to few chances.
Charlie Colkett produced a good cross to pick out Ben Gladwin inside the area, but the midfielder was unable to get his header on target and it flew wide.
The Reds then fashioned another chance as Rohan Ince won back possession before teeing up Jon Obika, but the striker’s shot deflected off David Mirfin and went out for a corner.
The home side were being kept at bay by an organised Iron defence, although they did go close just past the hour mark when Obika’s long-range drive was tipped around the post by Joe Anyon.
It was then Scunthorpe’s turn to attack again as Ivan Toney latched onto a ball from a corner before warming the palms of Vigouroux.
And they went even closer just before half-time with Morris planting his free-kick against the crossbar.
There was time for one last chance and it went the way of the visitors with Toney warming the palms of Vigouroux from a long-range free-kick.
Both sides had chances after the interval with Paddy Madden sending a tame shot straight at Vigouroux, before Obika forced Anyon into a good stop at the other end.
Vigouroux then had to be at his best to keep out Toney’s strike, before Jamie Ness skewed wide from the resulting corner.
With the game having reached the hour mark, Town opted to freshen things up with James Brophy replacing Brad Barry.
And the substitute nearly made an instant impact after latching onto a superb cross-field ball before cutting in, but Anyon was equal to the effort.
Town then made another change with John Goddard replacing Charlie Colkett, although it proved to in vain with Scunthorpe doubling their lead a minute later after Sam Mantom tucked home from close-range moments after coming on.
Luke Norris replaced Fankaty Dabo with The Reds needing to throw everything forward in a bid to get back into the game.
Vigouroux had to be alert to deny Madden late on while Goddard lashed wide at the other end.
However, Town did pull one back thanks to a stunning goal from Rohan Ince, who then went close moments later after thumping inches wide.
Norris then tried his luck twice in quick succession but wasn’t able to find the target with Town's relegation from League One confirmed at the final whistle.
TEAMS AND STATS:
SCORERS - Murray Wallace (5), Sam Mantom (72), Rohan Ince (85).
TOWN - Vigouroux; Barry (James Brophy 60), Rossi-Branco (C), Conroy, Dabo (Luke Norris 72); Ince, Thomas, Colkett (John Goddard 70), Gladwin; Obika, Ajose.
Subs Not Used - Henry, Ormonde-Ottewill, Rodgers, Starkey.
SCUNTHORPE UNITED - Anyon; Wiseman, Wallace, Mirfin, Townsend; Morris, Dawson (C), Bishop, Ness; Madden (Craig Davies 87), Toney (Sam Mantom 69).
Subs Not Used - Watson, van Veen, Toffolo, Holmes, Sutton.
BOOKINGS:
TOWN - Raphael Rossi-Branco.
SCUNTHORPE UNITED - Ivan Toney.
Referee - Nicholas Kinseley.
ATTENDANCE - 7,579 (363 Away Fans).
There will be reaction to Saturday's defeat and the club's relegation to the Sky Bet League Two from a number of players later this week.
