The 22-year-old midfielder had informed the Blues of his wish to join Richmond but Carlton officials had hoped to persuade him to remain.
Under the deal Collins, also 22, will move to Visy Park.
Collins was drafted by Richmond at pick 73 in the 2006 NAB AFL Draft. The Blues took Grigg at pick 19 in the same year.
Richmond’s General Manager of Football, Craig Cameron, said the Tigers were delighted to have secured Grigg after some days of negotiation.
"We believe Shaun will be a good fit for our side," he said.
"He’s got a bit of size for a midfielder, is hard at it, and has a really good engine, which will help us next year with the changes to the interchange system."
The Blues were similarly pleased with the swap, teaming Collins with an already potent group of small forwards following his two years and 25 games at Richmond.
"It’s pleasing to have a young player who is looking forward to playing for the Carlton Football Club and being a part of our exciting future," football manager Steven Icke said.
"There is a real Carlton connection as not only was Andrew recruited from Bendigo, the home of many Carlton greats, he is also the nephew of Peter Francis, who played in Carlton’s 1979 premiership team."
This is Carlton’s first trade during the exchange period.
Richmond have already offloaded one of their smaller players, with former No.4 draft pick Richard Tambling moving to Adelaide for a Gold Coast Suns end-of-first-round compensation pick as well as a third-round pick (currently No. 50).
Follow our complete coverage of the 2010 AFL exchange period from October 5-11. No trades are official until paperwork has been accepted by the AFL and formally recognised after 2pm on Monday, October 11.
Join the AFL trade conversation on Twitter: use #tradeweek in your tweets.
