Ulster will host Connacht in their Pro14 quarter-final on Saturday 4 May.
The provinces will kick-off at Kingspan Stadium at 17:35 BST with a place in the last four of the competition up for grabs.
Earlier this season Connacht claimed their first win in Belfast for 58 years with a 22-15 victory in October.
With one round of fixtures remaining Ulster are guaranteed to finish second in Conference B while Connacht have secured third spot in Conference A.
All four Irish provinces have secured their places in the knock-out stages of this season's competition.
Leinster will go straight into the semi-finals having topped Ulster's conference while Munster could still leapfrog Glasgow to take first in Conference A.