A by-election was held for the Sarawak State Assembly seat of Tanjong Datu on 18 February 2017 following the nomination day on 4 February 2017. The seat fell vacant following the death of its state assemblyman and Sarawak Chief Minister Adenan Satem from cardiac arrest on January 11, 2017. Adenan, who was also president of the Parti Pesaka Bumiputera Bersatu, won the Tanjong Datu seat in 2016 state elections when he defeated Jazolkipli Numan of PKR by polling 6,360 votes against 468 by Jazolkipli.