Munster and Ulster are both chasing a home semi-final, while Connacht are desperately hoping to secure the top-six finish that would see them compete in next season's European Champions Cup.
Munster will host the Newport Gwent Dragons at Irish Independent Park today, while Connacht go up against league leaders, the Ospreys at the Sportsground.
A second-string Ulster side will travel to face last season's beaten finalists, the Glasgow Warriors at Scotstoun.
Meanwhile, Leinster will finish-off their disappointing season at Murrayfield where they'll take-on Edinburgh.
All of today's matches have 3 o'clock starts.
