Abdallahi Matallah Saleck (Arabic: عبد الله مط الله سيك), also spelled as Abdellahi Matalla Saleck, is a Mauritanian human rights activist and anti-slavery campaigner who rose to prominence as a member of the Initiative for the Resurgence of the Abolitionist Movement. He served 743 days in prison between 2016 and 2018 due to his activism after being arrested at a protest in Nouakchott.