The Manchester United forward scored two goals and assisted Antony’s opener in the 3-1 victory over Arsenal, having played in Jadon Sancho to score United’s winner at Leicester at the start of the month.
It is the second time Rashford has received the accolade. The 1first time he received it was in January 2019.
United only played two league games in September as two of their matches against Crystal Palace and Leeds were postponed due to the death of the Queen.
Christian Eriksen was voted United’s player of the month by supporters due to his fine form across their four games. Eriksen started in the Europa League defeat to Real Sociedad and win against FC Sheriff, ties Rashford missed due to a muscular injury.
Rashford has not trained with United so far this week and it is unclear if he will be available for the Manchester derby at City on Sunday.
The 24-year-old has previously scored twice at the Etihad, both of them in victories for United.
United have a packed October, with nine fixtures to play in the run-up to the World Cup, which starts on November 20.
After the derby, United travel to Cyprus to play Omonia Nicosia in their third Europa League game, then face Everton at Goodison Park before three successive home games against Omonia, Newcastle and Tottenham.
United travel to Chelsea on October 22 and then host Sheriff and West Ham.