Sportal.co.nz 27.Feb.2014Getty Images
Tagicakibau, 31, a three-time World Cup representative for Samoa with 24 Tests, is to join the Stormers for their tour to New Zealand and Australia where they play the Crusaders, Chiefs, Brumbies and the Reds.
He has been playing for London Irish in the English Premiership since 2005-06.
The Stormers have been hit by injury concerns. They were forced to play two regular centres, Damian de Allende and Kobus van Wyk, on the wings in their shock 10-34 loss to the Lions last week.
This was on the back of losing Bryan Habana, Gerhard van den Heever and Joe Pietersen from last year's side when they went overseas.
Coach Allister Coetzee said on the Stormers website, iamastormer.com: "We've been looking for an experienced and strongly-built international wing for some time and Sailose Tagicakibau fits the bill perfectly.
"We've done our research on him, having tracked his progress for some time now.
"We have also built up a good understanding with London Irish and Sailosi comes highly recommended by [London Irish] director of rugby Brian Smith."
Coetzee said Tagicakibau would be able to play in Friday's match against the Hurricanes (although he hasn't been named to play) while his experience in New Zealand and Australia would be of great benefit to the side.
"I have no doubt that he will thrive in the Stormers environment and also, in the process, share his many experiences of top-level rugby with the younger, home-grown players in our squad," he said.