Ms Ardern stepped down as prime minister in January, saying she had “no more in the tank” to lead the country and she would also not seek re-election to parliament.
She quit parliament earlier this month.
Harvard University said in a statement she had been appointed to dual fellowships at Harvard Kennedy School and to a concurrent fellowship at the Berkman Klein Center.
“I am incredibly humbled to be joining Harvard University as a fellow — not only will it give me the opportunity to share my experience with others, it will give me a chance to learn,” Ms Ardern said in the statement.
She added on Instagram the fellowship at the Berkman Klein Center would not only be a chance to work collaboratively with the centre’s research community, but also to work on the challenges around the growth of generative AI tools.