Staveley is leaving her post as managing director and selling her shares, along with husband Mehrdad Ghodoussi, as part of an ownership restructure.
Staveley said on Friday: "Newcastle United is such a special, unique club and being a co-owner of Newcastle United has been an honour.
"Mehrdad and I have loved being part of this club and community and are extremely proud of the progress Newcastle United has made in recent years.
"Our ambition has always been aligned to the brilliant fans of this club - to create consistently successful teams that regularly compete for major trophies and generate pride across the globe.
"We are grateful to have played our part in setting up the club for even more future success. We will remain fans for life."
Newcastle chairman Yasir Al-Rumayyan said: "Amanda and Mehrdad will forever have our tremendous thanks and well-wishes as they move on to focus on their other business interests.
"We have achieved so much together since 2021, including achieving Champions League football in our first full season as stewards of this incredible club.
"The ownership group, together with CEO Darren Eales and the club's executive team, will continue to build on these foundations for long-term, sustainable success for the team and our amazing fans, and we are excited about the future prospects for Newcastle United."