The youngster signed a new contract with the Reds in October 2019 and has been a regular starter in the club’s development teams.
Kovar is the third young United to leave the club on loan this summer after Tahith Chong joined Werder Bremen and Aliou Traoré left for SM Caen.
The goalkeeper expressed his joy at completing the loan transfer and the possibility of further development away from United.
“First of all, I would like to thank everyone for the warm welcome, even on the training ground. Everyone has been great to me since I arrived, ”he said on the official Swindon website.
“It was a good time to come here and gain some experience in men’s football. I’m really happy that the club came to see me and gave me this opportunity.
“The gaffer spoke to me in a pre-season game at the Manchester United training game and he’s a really positive guy, he said he wanted to play football and that’s what I really looking. ”
United are also expected to loan James Garner and Dylan Levitt in the coming weeks, who are expected to stay in England and join competing clubs in the football league.