After contesting the last two seasons with Tanner Foust and Emma Gilmour as its two drivers, McLaren revealed in December that the duo would depart the team after achieving a best finish of second - in the 2022 Energy X-Prix in Uruguay and in Scotland's Hydro X-Prix last season.
Ekstrom, who raced for the Acciona Sanz team last year as a replacement for Carlos Sainz Sr following his back injury sustained on the Dakar Rally and Gutierrez, the 2022 XE champion with Lewis Hamilton's X44 team, will form an all-new line-up as XE prepares to bow out in its current guise at the end of the season.
It was confirmed to Motorsport.com in January that the hydrogen-based Extreme H championship that is due to begin in 2025 will not run alongside its electric forebearer, which will duly end its four-year run with November's Valley X-Prix in Phoenix.
Joining McLaren brings together two-time DTM champion Ekstrom and his old rival from the German tin-top series Gary Paffett, who is sporting director of McLaren's XE operation.
The 2016 World Rallycross champion finished second in the standings last year with Laia Sanz, and previously raced for the Abt Cupra team in 2021 alongside Claudia Hurtgen and Jutta Kleinschmidt.
Team boss Ian James said the signing of Ekstrom and Gutierrez was "a testament to our commitment to the series and underlines that we are competing in Extreme E with a clear goal: fighting for the championship".
He added that their "invaluable experience, raw talent and passion" would elevate the team and "the wider McLaren Racing family".
"I'm excited to join the NEOM McLaren Extreme E Team and wear the papaya colours," said Ekstrom.
"McLaren Racing has huge heritage and success in motorsport, so I hope that myself, together with Cristina, can extend the success story in Extreme E.
"I have known Gary for many years as we used to race against each other in DTM. With him at the helm of the team, I know everyone within the team will be super motivated and ready to push for the best result.
"I believe the 2024 season will be as competitive as ever, as most of the teams have learnt a lot from previous years.
"I will need to adapt quickly to the new team, learn from them, while also sharing my knowledge, so we can be in front of the pack from day one."
Gutierrez finished second in the standings alongside Sebastien Loeb with X44 in 2021, before going one position better in 2022.
Following Loeb's departure, Gutierrez and Fraser McConnell finished fourth in the standings last year.
The Spaniard said: "I would like to thank NEOM McLaren for counting on me to be part of this beautiful adventure with them in the Extreme E, since it is a championship that fights to give visibility and spark action to reduce the impact of climate change and promotes equality.
"I am very motivated to start working with the entire team. I cannot wait to get going in Saudi Arabia this month!"
The five-round championship begins in Jeddah with the Desert X-Prix on 17-18 February.