Tagicakibau helped Saracens to the Aviva Premiership title in 2011, the 27-year-old making 43 appearances in total during his three seasons at the club.
"We're very pleased to have secured Mike's services," Bristol head coach Liam Middleton told the club's official site.
"He attracted a lot of interest from other clubs so it's a significant boost to have his qualities in our side.
"Mike is a regular Premiership performer and has significant International experience. He has top-end speed and the outstanding ability of finding his way to the try line, which is testimony to his natural talent.
"What has impressed me most is his work rate in the field, and the physicality in his defence. Mike has good kick-chase skills which rounds his game off well.
"Importantly he is a top professional and a great character, and those are critical factors for us."
Gilbert has released a new line of rugby cleats. The Gilbert Virtuo 8S is part of the exciting new product. Check it out.
The Barbarians are one of the top invitational rugby sides with a long history and classic rugby jersey.
The Nike Tiempo is a solid rugby cleat and one of few styles still made from full-grain natural leather.
The Lions get ready for their matches with this green training jersey. It's what the players wear. Get in the Gear!
A cool looking all black rugby cleat with the high performance adidas is known for. Get in the Gear!
Wear the crest of the British and Irish Lions on your t-shirt. A great look for the summer.
The Lions are ready to get their Australia tour underway. They arrive in Perth on Monday.
The New Zealand All Blacks training jersey for 2013/14. Get in the Gear!
The USA Rugby Pro Alternate rugby jersey is perfect for any fan of the Eagles. Get yours to wear during the summer Test matches.
The NEW All Blacks 2013/14 jersey has arrived at World Rugby Shop. Dare to wear the colors of the All Blacks.