Thomas Frank has signed a new five-year contract at Brentford until the summer of 2027.
The 49-year-old Danish manager only secured a fresh deal with the Bees in January, which was to run until the end of the 2024-25 season.
Frank led the club to promotion to the Premier League 18 months ago as they ended a 74-year exile from the top flight, then finished 13th last season.
Brentford are 10th in the table and face Tottenham on 26 December.
On his new contract, Frank said: “The warmth, support and kindness every time I meet a Bees fan has been amazing and it gives me extra energy to continue the work going forward.
“We attacked the Premier League in the first season and we’re attacking it in our second season.
“I’m looking forward to hopefully continuing our progress and creating more magic moments together.”
Frank took over as Brentford head coach in 2018 after stepping up from his role as assistant to Dean Smith, who left to take over as Aston Villa boss.