The left-back, who has made 29 appearances for the Tykes in the npower Championship this season, joins the Robins as they look to seal the npower League Two title.
McEveley started his career with Blackburn before spells with Burnley, Gillingham, Ipswich and Derby preceded his move to Oakwell in the summer of 2010.
McEveley will compete with Callum Kennedy and Alessandro Cibocchi for a place on the left of Swindon’s defence.
Pedro stepped off the bench to send Chelsea into the FA Cup semi-finals after they beat Leicester 2-1 at the King Power Stadium on Sunday evening.
RB Leipzig came from behind at the Red Bull Arena to end a run of four winless games and defeat Bundesliga leaders Bayern Munich 2-1 on Sunday.