Williams was shown a red card by referee, John Lacey, in the 24th minute of the Cardiff Blues v Montpelier match for an alleged dangerous tackle on the Montpellier scrum half, Benoit Paillaugue
The Blues scrum half will now travel to Dublin on Thursday for the hearing. Jeremy Summers (England) has been appointed as the independent Judicial Officer for the hearing. The decision will be communicated in advance of this weekend's Round 4 matches.
Judgement Day is back at the Millennium Stadium for 2015 with the Welsh Rugby Union (WRU) and Regions confirming today that tickets will cost just £10 per head to see all four of Wales' GUINNESS PRO12 sides in action under one roof.
Battling Cardiff Blues produce a performance of full pride and heart in adversity as they lost out to reigning champions Leinster Rugby in a pulsating Guinness PRO12 encounter at BT Sport Cardiff Arms Park.
Cory Allen scored the only try of the game as Cardiff Blues edged an absorbing and dramatic Welsh derby with Newport Gwent Dragons at Rodney Parade to open 2015 in the Guinness PRO12 with a crucial victory.