The AFL approved Neale signing a three-year deal with the Magpies on Friday afternoon, closing out the first day of free agency.
The 33-year-old ball-winner leaves as an unrestricted free agent after the Lions clinched a third straight flag with their stunning seven-point grand final victory over Fremantle.
Brisbane chairman Andrew Wellington poked fun at Neale's switch to the "dark side" at the club's best and fairest event, where he finished third behind Will Ashcroft and Josh Dunkley.
"Take a last look at Lachie because he's going tomorrow to have some teeth removed and a bit more ink," Wellington joked on Thursday night, drawing laughter from the crowd.
Departing coach Chris Fagan hailed Neale's perseverance after stepping down as captain in January following the public breakdown of his marriage and almost missing the grand final through suspension.
"As we all know, he's been under a fair bit of pressure but it's never shown out on the field," Fagan said.
"(We) wish you all the best at your new club and with the rest of your life and whatever happens to you."
The Lions have been handed a second-round draft compensation - currently pick No.39 - with Neale reportedly raking in about $900,000 a season.
Toby Greene, another unrestricted free agent, was the first major domino to fall on Friday as the foundation Giant secured a late-career move to Geelong.
Greene, a triple All Australian and dual club champion, kicked 450 goals across his 15-year, 282-game tenure for GWS.
The 33-year-old cited family reasons for returning to his native Victoria and reunites with his close mate and former Giants forward Jeremy Cameron at the Cattery on a lucrative three-year deal.
GWS receive a second round draft selection as compensation, currently slated at No.26.
They also banked a third-round pick, No.46 at present, for losing ruckman Kieran Briggs to Richmond as an unrestricted free agent.
Key forward Joel Amartey's switch from Sydney to Carlton was also confirmed, with a second-round pick - currently No.36 - coming back to the Swans.
Amartey tallied 43 goals across Sydney's grand final-losing 2024 season but couldn't break back into Dean Cox's team for the 2026 finals after recovering from a partial Achilles tear.
Melbourne's 2021 premiership vice-captain Jack Viney is poised for a move with two years remaining on his contract after meeting with West Coast.
After being sidelined through injury for all but one game this season, the 32-year-old was told by coach Steven King there would likely be limited opportunities for him in the Demons midfield.
"Footy's gone that way mate," Viney told 10 News at Perth Airport on Thursday.
"So, took a bit to process early days, but we're here now, so we'll make the best of the opportunity. It (a deal) will get done."
Young Hawthorn forward Calsher Dear, meanwhile, has opted to stay at the Hawks on a two-year deal after weighing up a potential move to the Dees.
The 21-year-old, son of late 1991 Norm Smith medallist Paul Dear, burst onto the scene in his debut season with 25 goals from 17 appearances in 2024.
But the emerging tall has struggled to hold his spot through injury and internal competition, adding just 14 games in 2025 and 2026.
Hawthorn's key forward selection squeeze is set to worsen in 2027, with Gold Coast's restricted free agent Ben King expected to join Jack Gunston, Mitch Lewis, Mabior Chol and Dear.