Abdullah al-Tasnim (; born 1986), also known by the alias Nahid (), is a former Bangladeshi Islamist militant that used to be a top leader in Jamaat-ul-Mujahideen Bangladesh and Neo-Jamaat-ul-Mujahideen Bangladesh.
Abdullah al-Tasnim was born in Dhaka Division of Bangladesh on 1986 to a highly educated conservative family. al-Tasnim's father is the late professor Abdul Hamid and he also has at least two brothers. One of al-Tasnim's uncles was a professor at Jahangirnagar University and another was a secretary in the Government of Bangladesh. In 2004, al-Tasnim was pursuing higher secondary education at Tamir-ul-Millat Alia madrasa in Tongi, and he was admitted to the English department of Government Saadat College in Karatia, Tangail after passing Alim from the Tamir-ul-Millat Alia madrasa.
On a Friday in 2004, al-Tasnim attended a khutbah that was led by Shaykh Abdur Rahman at a mosque in Dhamrai, who noted down the names and addresses of al-Tasnim and others to identify the people that wanted to be part of the group. After expressing allegiance to Rahman, Rahman gave al-Tasnim the task to expand JMB's student wing. His brothers Abdullah al-Sohel and Taiyabur Rahman Hasan also joined the JMB student wing. On 19 December 2006, al-Tasnim was arrested by the police due to the 2005 bomb blasts that were done by JMB.
al-Tasnim then bailed out of jail in April 2014 and tried to go to Saudi Arabia before being approached by members of Neo-Jamaat-ul-Mujahideen Bangladesh who asked him to join Neo-JMB. On 18 September 2014, he was arrested again and sent to Kashimpur High Security Prison.
Seven years after his arrest, in 2021, Tasnim was interviewed under special arrangements at the Kashimpur Prison, and he said that he will probably never get out of jail and: