Trinity College in Dublin has racked up over €900,000 in student fines since 2011.
UCD and UCC took in almost €400,000 in the same period, while DCU collected almost 300,000.
Penalties are imposed on students for various reasons, including late library returns, overdue fee payments, late registration and parking violations.
According to reports €560,555 of the money collected by Trinity College, was from late library returns.
The policy at Trinity College library is 50 cent per day, which rises to €1 after two weeks and short loan fees are 25 cent an hour.
Union of Students in Ireland Vice President Annie Hoey has questioned the amount raised by the college through these fines asking if it is really a method of making money.