The Respect MP and former Celebrity Big Brother contestant made the comments in a video podcast about Assange, who has been granted asylum by the Ecuadorian embassy in London as he faces extradition to Sweden over sexual assault claims made by two women in 2010.
Although he described Assange's alleged behaviour, which includes trying to have sex with one of the women while she slept after having consensual intercourse with her the night before, as "sordid" and "disgusting", Galloway argued that his actions did not constitute rape "as anyone with any sense can possibly recognise it".
"I mean not everybody needs to be asked prior to each insertion," the 58-year-old said. "Some people believe that when you go to bed with somebody, take off your clothes and have sex with them and then fall asleep, you're already in the sex game with them.
"It might be really bad manners not to have tapped her on the shoulder and said 'do you mind if I do it again?' It might be really sordid and bad sexual etiquette but it is not rape."
Assange denies the claims and fears that if he is extradited to Sweden he will end up in the US, the country he angered in 2010 by publishing secret diplomatic cables on WikiLeaks.
The 41-year-old delivered a speech from a balcony of the Ecuadorian embassy, where he has been held since June 19, on Sunday (August 19) urging America to "renounce its witch-hunt against WikiLeaks".