The magazine cover features 15 women including New Zealand Prime Minister Jacinda Ardern, actresses Jane Fonda, Jameela Jamil and Gemma Chan, model Adwoa Aboah and teenage climate change campaigner Greta Thunberg.
The duchess herself doesn't appear on the cover. Editor-in-chief Edward Enninful said they discussed whether Meghan should be on the front cover from the beginning, but said in the end she "felt that it would be in some ways a 'boastful' thing to do for this particular project".
"She wanted, instead, to focus on the women she admires," he said. Meghan, who is on maternity leave from her royal duties after the birth of her son Archie, had worked on the project for seven months. She said she hopes readers will be inspired by the magazine's focus on the "values, causes, and people making impact in the world today."
Kate, the Duchess of Cambridge, was featured on the magazine's cover in 2016 for its centenary edition.