The award-winning artists are nominated for best original song for work on King Richard and No Time To Die respectively at the 94th annual awards on Sunday.
Beyonce is nominated for Be Alive, which features in the biopic of Richard Williams – father of tennis stars Venus and Serena Williams – and stars Will Smith in the titular role.
Her performance will reportedly be broadcast from a Compton tennis court where the world-class players used to train.
Eilish is nominated along with her brother Finneas O’Connell for No Time To Die, the title song from the latest instalment of the James Bond franchise.
The sibling duo have already racked up multiple wins for the song and are also scheduled to perform the following week at the 64th annual Grammy awards.
Both Beyonce and Eilish will perform the songs they are nominated for, as will Reba McEntire and Sebastian Yatra.
Yatra will sing Lin Manuel Miranda’s Dos Oruguitas from Encanto, and McEntire will perform Diane Warren’s Somehow You Do from Four Good Days.
Van Morrison, who is nominated for best song for Down To Joy from Belfast, was also invited to perform but is not able to attend the Oscars due to his tour schedule.
The song will therefore not be played at the ceremony, according to show producers Will Packer and Shayla Cowan.
Scores of big names have been named for presenting duties for the industry’s biggest night.
Stephanie Beatriz, DJ Khaled, Elliot Page, Jennifer Garner, comedian Bill Murray and skateboarder Tony Hawk, were among those most recently announced.
The list also includes Mila Kunis, John Travolta, Daniel Kaluuya and Wesley Snipes, as well as Zoe Kravitz, Lady Gaga, Lily James, Uma Thurman and Rami Malek.
Anthony Hopkins, who was named best actor last year, will also make an appearance at the ceremony which will take place at the Dolby Theatre in Los Angeles on March 27.
Oscars voting officially closed on Tuesday at midnight UK time.