Unite was forced to evacuate 320 people as a precaution from The Plaza, in Claypit Lane, after a burst pipe caused flooding overnight on Wednesday.
And with limited hotel spaces available in Leeds, some students had to travel to stay with friends or family.
The company said all of those affected have now been found alternative accommodation in Leeds.
It comes as many students are preparing to sit their end-of-year university exams this month.
A spokeswoman for Unite said: “All students have now been found alternative accommodation in Leeds.
“Unite treats the safety and security of our students with the utmost importance and we are very sorry this issue has impacted on our customers. We are working closely with our university partners and are working to resolve this issue as quickly as possible.”
The building is now closed while repairs are carried out.
Unite helped arrange a free cooked breakfast after the evacuation on Wednesday for those affected.
Students booked into hotel accommodation have also been booked breakfast and dinner by Unite, and have an allowance for lunches.
They will be able to claim for damaged possessions according to their tenancy agreements.
A University of Leeds spokeswoman said its “priority” was to minimise any impact on its 15 students affected.
They added: “We are working with Unite to contact these students directly to offer our own support and services.”
It is the latest problem to hit the building after a fault with a water paper on April 21.
The leak last month affected 50 students who were relocated for between three and seven days.