The 21-year-old midfielder made his debut for Benfica just last season and Spurs have the option to make his signing permanent at the end of the loan period.
Fernandes won the Portuguese title with Benfica last season playing 53 times for the club and scoring two goals in the Champions League.
He becomes Jose Mourinho’s first signing as Tottenham manager
In a recent interview, Fernandes, said he will settle in London alongside family who have already made the move.
“It’s a hard story. My family, they came to London because in Portugal, work is very hard and it’s very difficult to find work,” said Fernandes.
“They did not have a brilliant life but they have a good life here and this is one more motivation for me to be here today. They will help me to settle here.
“For me, it’s one big dream to come to this big club. This is a fantastic challenge that I have accepted and I have to win my challenge.”
By Acccelerate Sports