The 991 members of the 36 state Houses of Assembly are elected from single-seat constituencies using first-past-the-post voting; when vacancies occur, by-elections (or bye-elections) are called, scheduled, and administered by the Independent National Electoral Commission.

Ovuakpoye Evivie, the PDP nominee, defeated runners-up Ogaga Ifowodo (APC) and Michael Emumena Paul (SDP) by nearly 60% and over 5,500 votes.

[5][6][7] However, the election's successful conduct was overshadowed by the murder of a local vigilante by gunmen at Polling Unit 5 of Irri Ward 10 and the nonfatal shooting of another person in Oleh.

[13][14] On January 18, 2021, member for Kafin Hausa, Adamu Babban Bare (APC), died from an undisclosed illness suspected to be cancer.

[18] On April 29, 2021, the seat of Sabon Gari was declared vacant after member Aminu Abdullahi Shagali (APC) did not attend legislative meetings for a prolonged period of time and did not submit a requested letter of apology to the House of Assembly.