Frenchman Hadjar, 21, has made a big impression in his debut season with sister team Racing Bulls, taking his first podium with third place at the Dutch Grand Prix at the end of August.
British-born Lindblad, who also has Swedish nationality and Indian heritage through his mother, moves up from Formula 2 to partner New Zealander Lawson and will be the sole rookie on the 2026 grid.
Tsunoda's departure leaves Formula 1 without a Japanese driver on the starting grid, but Red Bull said he will remain within the 'family' as test and reserve driver for the first season of a new engine era. He will also serve as Racing Bulls reserve when compatriot Ayu Iwasa, this year's Japanese Super Formula champion, is not available.
"We believe Isack can thrive alongside Max and produce the magic on track," said Red Bull principal Laurent Mekies.
The role of teammate to four-times world champion Verstappen, who could yet add a fifth title in a row at Sunday's season-ending Abu Dhabi Grand Prix, has been something of a poisoned chalice for a string of hopefuls.
Verstappen, the absolute number one driver, will start 2026 with his fourth different teammate since the last race of 2024. No teammate has come close to the Dutch driver's relentless form since Mexican Sergio Perez took four podiums in the first five races last season and then suffered a dramatic loss of pace before departing.
Before him, Alex Albon - now at Williams - and Pierre Gasly - who moved to Renault-owned Alpine - also struggled to keep up. Lawson started this season as the incumbent but was replaced by Tsunoda after two races without scoring.
The Japanese driver has been completely eclipsed by Verstappen, with the champion winning seven races and scoring 396 points while Tsunoda's tally stands at a mere 33.
"After all the hard work I have put in since joining the junior team, it’s such a great reward," said Hadjar. "I’ve had many ups and downs throughout my career, and they kept believing and pushing me.
"I feel ready to go... and I am happy and proud they feel the same. It's an awesome move, to work with the best and learn from Max is something I can’t wait for."
Lindblad will take his place as the 20th Red Bull junior driver to reach Formula 1 and he recognised the challenge ahead.
"I know there’s a lot to learn, but I’m ready to work closely with the team and rise to it. I can’t wait to get started, it’s going to be an exciting year," he said.
Team boss Alan Permane said Lawson, 23, and Lindblad, 18, would be a strong and dynamic pairing.
"He (Lawson) has excelled when conditions have been at their hardest and we look forward to building on this in 2026, while Arvid’s rapid progression marks him as one of the standout young talents in the sport," he said.