The signing of the 34-year-old is the biggest in Super League history, and 70,000 people agreed when they attempted to access the club's website once the announcement was made.
Wolfpack owner and Canadian-based Australian mining and resources entrepreneur David Argyle is one of the masterminds behind the signing, and hinted there could be at least two more big names to join the roster in 2020.
Speaking on Sky Sports Radio this morning, Argyle said Williams' star power has already made an impact on Wolfpack sponsors and memberships.
"We have a really good IT department and server, and it crashed. We had 70,000 people trying to access it the minute it went live," he said.
"Some very large companies have contacted us to get involved. I'm meeting a producer from Hollywood who is flying out on Sunday from LA to meet with me, he wants to shoot the true, gritty behind the scenes of how and why we're here, the story of our road to the Super League."
Williams' addition to the Wolfpack adds to their incredible but short history. They secured promotion to the Super League in September in just their third year of existence.
The former Sydney Roosters and Canterbury forward returns to rugby league after completing his second stint with the All Blacks for whom he won the Rugby World Cup in 2015 and 2011.
He won NRL premierships with the Roosters in 2013 and the Bulldogs in 2004, and will now look to add a Super League title to his glittering resume.
"Toronto Wolfpack has established themselves as a multicultural and economic powerhouse, not only in the city but across the world," Williams said.
"The club has big ambitions and big goals. I want to be part of all this and do all I can to help reach those lofty goals.
"On the field, I'd like to bring high-quality play and do all I can for the betterment of the team.
"Off the field, I'd like to use my experience to mentor the young players and be helpful where I am needed."
Toronto chairman and CEO Robert Hunter said the signing is a huge shot in the arm for rugby league, not only in Canada but internationally.
"The excitement he will bring to the sport of rugby league in this country will be incredible," Hunter said.
"Having someone of his talent join the Wolfpack will greatly raise the profile of the club, and also help move the game forward globally.
"Sonny is a phenomenal athlete and we believe he is rugby's LeBron James and his addition to our league is comparable to when David Beckham joined LA Galaxy."
Williams will make his first official appearance as a Wolfpack player at a media conference at Arsenal's Emirates Stadium in London next Thursday.