The 29-year-old centre-back arrives at his boyhood club after signing a two-and-a-half-year contract and becomes Eddie Howe's fifth acquisition of the January transfer window.
Burn was originally part of the Magpies' youth set-up before being released aged eleven, and he returns to the club almost two decades later having become an established Premier League defender.
Burn said: "I'm buzzing to be here. I never thought I'd be in this position so to be a Newcastle player and to be around St. James' Park, it's something I've dreamt of since I was a kid.
"I can't wait to step out in the shirt and to see what it feels like. From sitting in the East Stand as a kid to now, it's crazy. I'm excited to get started."
Eddie Howe said: "I'm delighted to bring Dan back to the North East. He knows exactly what it means to represent this club and he will be a big presence for us on and off the pitch."We have been very keen to add competition defensively and Dan fits the profile we have been looking for. He is naturally left-footed, which provides further balance to our backline, and he will be a great addition to the group."
After being released by the Magpies as a youngster, Burn began his ascent into the professional game with spells at clubs including Blyth Spartans and Darlington, eventually making his Football League debut for the Quakers in 2009.
A series of impressive appearances in a Darlington shirt led to interest from a number of top-flight clubs and Burn was signed by Fulham - then in the Premier League - in summer 2011.
He joined Yeovil Town on loan a year later, playing a key role as the club sealed promotion to the Championship for the first time in its history, before continuing his development with a loan spell at Birmingham City during the first half of the 2013/14 season.
Following the expiry of his Fulham contract, Burn joined Wigan Athletic and became a key member of the Latics squad in the Championship, earning the club's player of the year award during the first of his two seasons with the club.
Despite moving to Brighton & Hove Albion in August 2018, he began the 2018/19 back at the DW Stadium on loan and would have to wait until January to make his Albion debut.It was during the 2019/20 season that Burn began to make a significant impact at the Seagulls, becoming a mainstay in the club's backline, with his 6ft 7ins frame effective at both ends of the pitch.
Burn arrives back on Tyneside after making 74 Premier League appearances for Brighton, added to the nine Premier League outings he made during his time at Fulham.
