Sayed Nizar Al‑Wadaei is a Bahraini human rights defender and the brother‑in‑law of Sayed Ahmed Al‑Wadaei. He was arrested in March 2017 alongside his mother‑in‑law Hajer Mansoor Hassan and cousin Mahmud Marzuq Mansoor, accused of planting fake bombs. They were convicted in October 2017 following a trial marred by allegations of torture and lack of evidence (as no DNA or fingerprints were presented) leading to three‑year sentences widely condemned as collective punishment and reprisals . While imprisoned in Jau, Sayed Nizar reportedly developed tuberculosis symptoms in late May 2022 after sharing a cell with an infected prisoner. When he complained, he was placed in solitary confinement and denied testing until 6 June 2022, with no treatment disclosed.

He was released in April 2024 among over 1,500 people pardoned and released by King Hamad bin Isa bin Salman Al Khalifa, to mark the Eid Al-Fitr and the silver jubilee of the king taking power.