Tainio will arrive on a free transfer as he will be out of contract at Auxerre in July.
The Tornio-born player began his career at FC Haka in his homeland before choosing to join Auxerre in 1997 from a host of clubs that were chasing his services. He has since made over 150 appearances for Guy Roux's side.
Tainio has won 25 full caps for Finland, scoring five goals.
"We are delighted that we have been able to secure Teemu now and do not have to wait until the summer to make the signing," commented Sporting Director Frank Arnesen. "We know many other top clubs were keen on him.
"He is a versatile midfielder who can play anywhere across the middle."
For his part, Tainio is looking forward to pulling on the Spurs shirt and performing in the Premiership.
"I am thrilled at the prospect of playing for Tottenham and in the Premiership," he said. "It is one of the best leagues in the world. I look forward to joining everyone in July."
The Club has not only been busy in the winter transfer window, we can also announce a new arrival for the summer. Finland international midfielder Teemu Tainio will join the Club in in July from French side Auxerre. The 25-year-old has signed a pre-contract agreement and will link up with the squad at the beginning of pre-season.