The front row welcomes back team captain Rory Best who returns from injury to line up beside Bryan Young at loosehead and tighthead Tom Court.
Stephen Ferris also returns to action with Roger Wilson dropping out of squad and Neil Best named as back row cover on the replacements bench.
In the backs, Williams has made three changes with the half-back partnership of Isaac Boss and Paddy Wallace replacing Paul Marshall and Niall O'Connor.
Bryn Cunningham returns to start at full-back with youngster Mark McCrea named on the bench.
Meanwhile, Munster's 2006 Heineken Cup-winning captain Anthony Foley will become the first player to play 200 times for the province when he leads them out for their re-fixed game against Ulster.
For the trip to Belfast, Munster coach Declan Kidney has made just three changes in personnel to the side that accounted for the Ospreys last time out in the league.
The one back-line change sees Peter Stringer return to the starting line-up where he will partner Paul Warwick at half-back, while up front there are four changes, two of them positional.
With Donncha O'Callaghan omitted along with all those who started against Saracens in Sunday's Heineken Cup semi-final, Donnacha Ryan slots into the second row alongside Mick O'Driscoll.
John O'Sullivan, who wore the number 7 jersey in an impressive display against the Ospreys, swiches to the blindside with Niall Ronan, recovered from a back strain, returning to the openside spot.
The side will be led at number 8 by Anthony Foley who will create history by becoming the first player to win 200 caps for Munster.
ULSTER: Bryn Cunningham; Tommy Bowe, Andrew Trimble, Rob Dewey, Mark Bartholomeusz; Paddy Wallace, Isaac Boss; Bryan Young, Rory Best (capt), Tom Court, Carlo Del Fava, Ryan Caldwell, Matt McCullough, Kieron Dawson, Stephen Ferris.
Replacements: Nigel Brady, Justin Fitzpatrick, Justin Harrison, Neil Best, Paul Marshall, Niall O'Connor, Mark McCrea.
MUNSTER: Shaun Payne; Brian Carney, Barry Murphy, Kieran Lewis, Anthony Horgan; Paul Warwick, Peter Stringer; Federico Pucciariello, Frankie Sheahan, Tony Buckley, Donnacha Ryan, Mick O'Driscoll, John O'Sullivan, Niall Ronan, Anthony Foley (capt).
Replacements: Sean Cronin, Darragh Hurley, Mark Melbourne, James Coughlan, Gerry Hurley, Jeremy Manning, Keith Earls.
Referee: Alan Lewis (Ireland)
Touch Judges: Alan Rogan and John Carvill (both Ireland)
Television Match Official: Dudley Phillips (Ireland)
Say What: Matt Williams (Ulster) - "Munster were magnificent as always, any other team would have lost that game (the Heineken Cup semi-final) but they hung in for the win. Mentally, they are a tough group of men.
"Listen, it does not worry us who they bring up. This is all about us. Their players will want to front up against us no matter who it is. It is just a normal match at the end of the day.
Declan Kidney (Munster) - "We've a great squad and it's a great opportunity for everybody to get a game. Obviously it's a huge challenge going to Ravenhill - it's a challenge at the best of times.
"(In Munster's win at Ravenhill last season) I think we were down quite a bit at half-time, but they (Ulster) came out and showed great resilience in the second half and we came out and were fortunate to win by a point or two. Forewarned is forearmed - I wouldn't expect us to get away with anything like that on Wednesday night.
"The fact that the lads beat the Ospreys would obviously forewarn Ulster that we'll be looking forward to the game. There's a video now available on that Ospreys game.
"Sometimes the work of video analysts gets understated. You have to say that Ospreys weren't too sure what they were up against, but now Ulster would have seen the game and would have been able to do their homework."
Top Scorers: 2007/08 Magners League - Points: Ulster: Niall O'Connor 54; Munster: Paul Warwick 110; Tries: Ulster: Tommy Bowe 3; Munster: Paul Warwick, Denis Leamy, Donnacha Ryan, Tony Buckley, Doug Howlett 2 each.
PREVIOUS LEAGUE MEETINGS:
Saturday, December 8, 2001 - Semi-Final - Ulster 9 Munster 15, Lansdowne Road
Friday, September 27, 2002 - Ulster 26 Munster 17, Ravenhill
Friday, January 3, 2003 - Semi-Final - Munster 42 Ulster 10, Thomond Park
Friday, October 10, 2003 - Munster 15 Ulster 16, Musgrave Park
Friday, March 5, 2004 - Ulster 36 Munster 13, Ravenhill
Saturday, November 6, 2004 - Ulster 3 Munster 24, Ravenhill
Friday, March 18, 2005 - Munster 21 Ulster 15, Musgrave Park
Saturday, December 3, 2005 - Munster 17 Ulster 20, Musgrave Park
Friday, March 3, 2006 - Ulster 27 Munster 3, Ravenhill
Saturday, September 30, 2006 - Munster 21 Ulster 13, Musgrave Park
Friday, March 23, 2007 - Ulster 21 Munster 24, Ravenhill
Saturday, March 22, 2008 - Munster 42 Ulster 6, Musgrave Park
- Ulster have gained just one victory in their last four matches in the Magners League - a 18-6 win at home to Connacht on April 11
- The Ulstermen have won their last four games at Ravenhill in all competitions
- Munster, who are through to their second Heineken Cup final in three seasons, have won three of their last four games in the Magners League
- Munster have won their last three encounters against Ulster, and have won on two of their last three visits to Belfast