The 32-year-old Spaniard has joined Bayern for just £5 million after five seasons with Champions League winners Real Madrid.
It's an extremely small fee for someone who has achieved so much in the game, and at 32, still has something to offer on and off the pitch.
talkSPORT pundit Richard Keys has had his say on the transfer, claiming it is the best business he has seen completed so far during this transfer window.
Keys tweeted: "Great result for Hull. They couldn't afford to get tied up in Europa League. And £5m for Alonso? Best piece of business this window."
You can't really argue against Keys's statement. With how inflated prices in the transfer market are at the moment, signing a player of the Xavi Alonso's calibre for £5 million is an absolute bargain.
However he might have forgotten about the other world class player that Bayern bagged very early this summer in Robert Lewandowski. The 26-year-old Pole's contract at Dortmund expired this summer and Guardiola was able to snap him up on a free transfer.
Should he have had a few more years remaining on his deal with Jurgen Klopp's side, he would surely have been worth £35 million+.
Alonso will be joining up with Spanish compatriot, Pep Guardiola, at the Bundesliga champions, and will provide world class cover with injuries to Bastian Schweinsteiger, Javi Martinez and Thiago Alcantara.
The Bavarians also sold pivotal playmaker Toni Kroos to Madrid for £20 million shortly after the World Cup, so recruiting Alonso will help boost Guardiola's options in centre of midfield.
Who do you think has been the best bit of transfer business this summer?