Attenborough recorded new narration for the hour-long special, which sets eight extraordinary sequences from Planet Earth II and Blue Planet II to new and rearranged music.
"Working with David on so many of his magnificent programs celebrating nature and our planet has been a joy for me," Zimmer said in a press release. "I am constantly inspired by what he is able to capture, and the collection of sequences featured in Planet Earth: A Celebration is truly special."
The string section of the score was performed by the BBC Concert Orchestra, with U.K. rapper Dave accompanying on the grand piano.
"The BBC has curated this amazing collection of sequences from two of the most talked about natural history series of recent years, Planet Earth II and Blue Planet II, as a spectacular treat for the viewers," said Tony Hall, the BBC's director-general.
"With brand new narration from the brilliant David Attenborough, a new score from Hans Zimmer and the team at Bleeding Fingers played by the BBC Concert Orchestra with Dave on the piano, this thrilling journey around the world promises to lift everyone's spirits."
No premiere date has been announced yet.