The 60-year-old politician backed frontrunner Corbyn in a 3-minute interview he gave to LBC late on Thursday.
"The chance of a fresh start, a Labour start, is quite an intoxicating idea," he said. "If Jeremy were to win, everyone on the left will rejoin the Labour party."
"My only surprise is that Jeremy is doing quite so well... He's the most unspun individual in British politics. He doesn't even spin the colour of his beard or the clothes that he wears."
Galloway added: "He doesn't spin his words, he says what he believes...and he's always said it. That can't be said for any of his rivals, who've been flip-flopping around."
Article continues below interview audio clip
The former respect MP said he felt people were "fed up of the Blairites", and that Corbyn would "re-energise" sidelined voters who had ditched the party.
Pressed by LBC presenter Iain Dale to give a definite answer on whether he would seek to rejoin a Corbyn-led Labour Party, Galloway said he'd happily return "pretty darn quick... hundreds of thousand would".
Galloway had sat as an MP, first in Glasgow, then in Bethnal Green & Bow, for Labour since 1987, but was removed from the party after being found guilty of bringing it into disrepute.