Queen's University in Belfast is carrying out an investigation into how a "Brits Out" poster was displayed at freshers' week.
The youth wing of the party Ogra Shinn Fein displayed a poster on Thursday featuring an image of 1916 Easter Rising leader James Connolly and the words "Brits Out".
In a statement, Queen's University said it is investigating issues relating to the Students' Union Freshers' Fair and the relevant disciplinary measures will be applied as appropriate following the investigation.
It said: "The University is committed to creating and sustaining a harmonious environment free from language or materials that are likely to be provocative or offensive, as reflected by the University's Equality and Diversity Policy. In line with the University's core values, Queen's expects all of its staff and students treat each other with dignity and respect."
Ulster Unionist Party MLA Andy Allen said British citizens find the slogan "Brits Out" offensive.
He said: "Sinn Fein's nonsense response to the 'Brits Out' poster on their youth wing's stall at Queen's Freshers' Fair is evidence they know they have been caught out and their respect agenda does not flow both ways.
"As both a former soldier in the British Army and a British citizen, I feel the poster does nothing but cause polarisation.
"In 2019, this polarisation should be consigned to the past and we should be working to deliver for all our citizens."
Queen's Young Unionists chairman Nathan Redmond said the slogan used by Sinn Fein is not acceptable language.
Mr Redmond said: "Sinn Fein are very fond of talking about equality, rights and respect, portraying themselves as the guardians of all that is wholesome and defenders of the Belfast Agreement.
"However, it never takes long until the mask slips and the true nature of Sinn Fein is laid bare for the world to see. So much for a shared future.
"Quite incredibly, this slogan was below a heading claiming Sinn Fein were anti-racist.
"It would appear that for Sinn Fein the slogan 'Brits Out' is acceptable language but, as far as we are concerned, it is most certainly not."