The 26-year-old, who is capable of operating in a number of different positions in the final third of the field, has signed a contract with the Spanish giants until the summer of 2027.
"Valencia CF and Brentford FC have reached an agreement for the signing of Sergi Canos on a four-year contract, through to June 30th, 2027," read a statement on Valencia's official website.
Canos represented Barcelona during his youth career before leaving for Liverpool in 2013, but he only made one first-team appearance during his time with the Merseyside giants.
The forward had a loan spell at Brentford during the 2015-16 season before joining Norwich City, but he only made six appearances for the Canaries before returning to Brentford on a permanent deal.
Canos has managed 36 goals and 33 assists in 249 appearances for the Bees, but he only made five Premier League outings last term and ended the 2022-23 campaign on loan at Olympiacos.
A successful spell in Greece saw Canos score four times in eight league appearances, before he returned to Brentford for the start of pre-season training.
There has been a host of speculation surrounding his future, though, and it has now been confirmed that he made the move to Valencia on a long-term deal.
Canos has become Los Che's third signing of the summer market after Cenk Ozkacar and Pepelu.
Valencia finished down in 16th position in La Liga last season, which proved to be their lowest spot at that level of football since being relegated to the Segunda Division in 1986.
Ruben Baraja's side have made an excellent start to this campaign, though, beating Sevilla 2-1 and Las Palmas 1-0 in their first two matches to collect six points from an available six.