Fleur Darkin, artistic director of Scottish Dance Theatre, and Mike Stirling, head of Beano Studios Scotland, have also been appointed.
Mr Wallace, a columnist for GQ, is currently working with two US networks developing pilot scripts.
The 40-year-old said he was "very proud to be from Dundee."
He said: "I've lived in different cities and different countries, but once you're a Dundonian, you're always a Dundonian.
"It's a proud city, and a determined one, but Dundee doesn't take itself too seriously.
"It's the home of jam, jute and journalism, yes - but it's also the home of artists, designers and inventors.
"And it's a funny city. I'm very proud to have been asked to be an ambassador.
"Some people would be happy being asked to be ambassador to Barbados or Fiji - I'll take Dundee."
Dundee's existing ambassadors include Emmy award-winning actor Brian Cox and Deacon Blue frontman Ricky Ross.
Mike Stirling, who was previously editor-in-chief of the Beano, said: "This is a city where comics are taught as a subject at university.
"If that's not a signal of outstanding creativity, I don't know what is."
Fleur Darkin, who directs Scotland's national contemporary dance company from its base at Dundee Rep, said: "Our productions are Dundee made and then we export what we do to the rest of the world.
"Being based in Dundee is a blessing for us, because it's very easy to live and work here and there are good conditions for experimentation."
Dundee-born writer and broadcaster Danny Wallace has been announced as one of three new official ambassadors for the city.