Abang Haji Abdillah

Datu Patinggi Abang Haji Abdillah (13 October 1862 – 21 November 1946) was a Sarawakian politician in Sarawak who participated in the movement opposing cessation to the British Empire.

He was the son of Datu Bandar Abang Haji Mohammad Kassim; who served as mayor of Kuching under the White Rajah's administration.

Abdillah stated his support for the anti-cession movement of Sarawak as such:"My people and I would never agree with the cession of Sarawak to the British Crown!...We cherish the independence of this state where we were born..." "Saya dan rakyat tidak bersetuju dengan penyerahan Sarawak kepada Tanah Jajahan Mahkota British!...Saya dan rakyat mencintai kemerdekaan negeri ini, tanah tumpah darah saya..." In a meeting with British officials, he protested the cession of Sarawak to the British Empire; claiming that the cession was illegal as it was not accepted by majority of the Sarawakian.

Abdillah was a major proponent of reinstating Anthony Walter Dayrell Brooke as the fourth White Rajah of Sarawak.

All government officials in Sarawak, European and Asian alike, were sent Circular no.9, which stated that they would be fired if any of them continued to support the anti-cession movement.