Leinster can regain the top-spot in the table and virtually guarantee a home semi-final with a win over an Ulster side that are looking to secure their play-off place with a win.
Kick-off in Belfast is at three o'clock.
Meanwhile, there's an all-Welsh double-header in Cardiff today.
The Blues take-on the Ospreys at half-past two before the Dragons and the Scarlets go head-to-head at 5pm.
