The 26-year-old centre-back, who is included in 1.3% of fantasy football teams at time of writing, has been a key member of the Seagulls defence since their promotion to the Premier League last season.
And Dunk has agreed terms on new long-term deal, with the contract set to be ratified inside the next 48 hours.
Dunk is an academy product at Brighton, having made his debut while the club were in League One in 2010.
He established himself as a first-team squad member after returning from a loan spell at Bristol City in 2013/2014.
He made 43 league appearances during their promotion-winning 2016/2017 season, and since then has made 41 Premiership appearances.