The five-times capped international will be added to a back-three which includes Wales full back Liam Williams and summer tourist Jordan Williams, as well as new addition Harry Robinson from the Blues.
Tagicakibau made 52 appearances for Saracens over two spells from 2009-2014, playing an important part in the side’s back-to-back Premiership final appearances and lifting the title in 2011.
The 29-year-old began his career at Air NZ Cup province Taranaki before starring for London Welsh and Bristol. He made his international debut for Fiji in 2007 and was a member of the Fijian squad for Rugby World Cup 2011.
The Scarlets have been keen to bolster their attacking options after securing a Rugby Champions Cup place by finishing sixth in the RaboDirect PRO12 last season and head coach Simon Easterby is convinced Tagicakibau will provide extra firepower and ferocity out wide.
“He has great line-breaking ability but, more importantly, he’s an excellent defender,” said Easterby.
“We have made it clear for some time that we are looking to strengthen our firepower out wide and, with the addition of Michael, and Harry (Robinson), we believe that we will have a very destructive back three in amongst a powerful backline.
“Michael has international experience with Fiji and has experienced success with Sarries – we’re looking forward to seeing him in action here at Parc y Scarlets and he will undoubtedly be a significant boost to the squad.”
Tagicakibau said: “I’m really looking forward to joining Scarlets and challenging myself in a new environment.
“The region has some great players in the back line and I’m excited about being part of a club that has a strong ethos of running rugby. I’m keen to make my mark.”