A proud Muslim, Williams posted to social media on Sunday night saying he would be in Christchurch "later in the week to show love and give donations to the Christchurch Masjids for the people effected in this tragedy".
The Blues confirmed the 51-test midfielder would not play against the Highlanders at Eden Park.
The match would count as one of the two Super Rugby fixtures he must miss as an All Blacks player ahead of this year's World Cup.
Williams' confirmation of his trip to Christchurch followed an emotional video he posted on Friday after the terror attacks.
In the video he cried and expressed his hurt and distress about the shootings.
Friday night's match in Auckland would be the first for the Blues since Williams led them to their first victory of the season after being handed the captaincy of the team.
The 28-20 win against the Sunwolves at North Harbour Stadium on March 9 came after the franchise had lost the first three matches of their 2019 campaign.