The 35-year-old was the life and soul of a post-Baftas bash in London hosted by movie mogul Harvey Weinstein.
Having split from girlfriend Nicole Beharie last month, all eyes were on the Killarney man when he was spotted chatting to Oscar-nominated actress Jennifer Lawrence, star of hit movie 'Silver Linings Playbook'.
Another party-goer he seemed pleased to see was 'Hangover' star Bradley Cooper, whom he greeted with a warm hug at London's LouLou club in Mayfair.
Prior to attending the awards ceremony, the actor was a guest on the BBC's 'Graham Norton Show' where he recounted how he regretted inviting his parents, Josef and Adele, to the premiere of his sex drama 'Shame' in Venice in 2011.
So it was a relief when his mother cancelled at the last minute due to a back injury, meaning that he only had to sit through the film with his father.
"At the time, I thought it was a good idea to invite them to the premiere. It was kind of awkward but they're open-minded people. At the last minute, my mother ended up not turning up, over her back or something, so I didn't have to worry about her, but my dad sat behind me and he patted me on the shoulder at the end," he told host Norton.
However, he explained that his family have become more than comfortable with his media persona -- to the extent that his father surfs the internet looking for gossip and film reviews. "My dad follows my career and tells me what I am doing before I know what I am doing.
"He has me on Google alerts. It's sweet and creepy at the same time," he said.
Fassbender is filming 'Frank' in Ireland, in which he plays the leader of an avant-garde band who come to the country to record.