The German and his Danish team-mate have both scored points this season, with Hulkenberg's seventh place in Australia in April their best result of the campaign, and their retention came as no surprise.
Between them they have started 346 grands prix.
Haas are eighth of 10 teams in the constructors' championship going into this weekend's Dutch Grand Prix at Zandvoort, the 13th round of 22.
"I think it’s safe to say that we’ve had an extremely solid driver pairing this season in Formula One and ultimately there was no reason to look to change that moving forward," team principal Guenther Steiner said in a statement.
"Kevin is obviously a very well-known quantity to us, and I’m delighted he’ll return for what will be his seventh season in Haas colours.
"On the other side of the garage, Nico’s simply slotted in without fuss or fanfare and proved himself to be a valuable member of the team."
Hulkenberg holds the Formula One record for most starts (193) without ever standing on the podium.
The German made a full-time comeback with Haas this season after replacing dropped compatriot Mick Schumacher and has reached the top 10 shootout in qualifying on six occasions.
"It’s nice to get things sorted early for next season to just keep the focus on racing and improving performance," said the 2015 Le Mans 24 Hours winner.
"We're competing in a very tight midfield and I’m looking forward to building on what we’ve done together so far and taking that forward into 2024."
Magnussen, 30, returned to the team at short notice in March 2022 after they fired Russian Nikita Mazepin following Moscow's invasion of Ukraine.
The Dane earned Haas a first pole position in a wet Brazilian qualifying last year and reached his 150 career races in Austria last month.
