The 34-year-old South Korean, whose music video is the second most watched YouTube clip in history, is the first east Asian pop star to address the historic organisation.
The speech will be Psy’s first public address in English, and he has picked the perfect venue – an organisation that Harold Macmillan once called ‘the last bastion of free speech in the Western world’.
The union, which exists independently from Oxford University and its students’ union, has previously welcomed welcomed high-profile figures from Jimmy Carter to Michael Jackson to speak to its members.
Psy, whose full name is Park Jae-sang, travelled from Paris by Eurostar and said he was visiting the UK for three days.
He stopped briefly to pose for photographers and sign autographs at St Pancras station in a sleeveless leather jacket, cropped trousers and yellow-rimmed sunglasses.
He said it was ‘really exciting’ to be in the UK and ‘a great feeling’ to be greeted by so many people.
The rapper became a worldwide sensation when his humorous single Gangnam Style single shot to number one in the UK in September.
The video shows Psy making fun of the extravagant lifestyle of the residents of Gangnam, a neighbourhood where he grew up in the South Korean capital, Seoul.
‘The president and Psy are both from Gangnam – the area where the eponymous hit song takes its name.’
Psy said: ‘I’m going to Oxford today, it’s really exciting, I’m looking forward to it.’
His signature dance involves him prancing like a horse and wildly gesturing while posing in a sauna, a stable and even on the toilet.
Nobody was more surprised by the success of the video Gangnam Style than Psy, a musician with a decade-long career in his homeland who never thought he would break overseas.
He said: ‘The YouTube video never targeted foreign countries. It was for local fans.
‘My goal in this music video was to look uncool until the end. I achieved it.’
The video’s popularity owes much to Psy’s zany outfits and outlandish dance moves.
Parodies have popped up from South Korea to the United States, with everyone from prisoners to royal Zara Phillips recreating the video.
Even a few of South Korea’s normally staid presidential candidates are imitating Psy’s moves in an appeal to voters.
The song was meant as a commentary on the rampant materialism and emphasis on appearance of today’s South Korea – particularly in relation to Gangnam, which Psy terms Seoul’s Beverly Hills.
The musician explains: ‘It is too hot, and the economy is so bad. So I just wanted the song – lyrics, dances and everything – to be full of gusto.’