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.
The Welsh stage of the Premiership Rugby 7s Series explodes into life at BT Sport Cardiff Arms Park this Saturday - and fans attending a night of thrilling regional rugby will also be showing their support for the #StayStrongForOws campaign.
In its sixth year the Blues Cup once again showed to be huge hit throughout the region and is a great advert for the community game as each of the six finalists across the three age groups produced rugby of an outstanding level resulting in 14 tries.
Inspired Cardiff Blues enjoyed Judgement Day at the Millennium Stadium as they secured a tense 17-13 win over regional rivals Scarlets in a feisty and enthralling encounter in the RaboDirect PRO12 on Easter Sunday.