The winger will now head to the club for a medical and to sign his contract ahead of an official presentation.
"FC Barcelona and Real Betis Balompié have reached an agreement for the transfer of Cristian Tello to the Andalucian side for four million euros with a potential one million more to come," the club said in a statement on their official website.
"FC Barcelona reserves the right to participate in the future sale of the player."
The 25-year-old joined Barcelona B in 2010 and although he did manage to break into the first team, he failed to become a regular at Camp.
It's little surprise to see Tello move on, after spending the last couple of seasons on loan at Porto and Fiorentina, and we wish him all the best for the future.