Abdul Aziz bin Muhammad bin Saud was the second ruler of the First Saudi State and son of Muhammad bin Saud. He was also the son-in-law of Muhammad bin Abdul Wahhab. He ruled from 1765 until 1803.

During his reign, the grasp of the House of Saud extended into Riyadh with Abdul Aziz's victory there and subsequent conquest. This victory allowed the House of Saud to rule all of Nejd. Their military success and orthodox approach to religion won them great support in the area. Their standing was also boosted by Abdul Aziz's practice of holding open meetings where tribal elders could meet with him, allowing access to their ruler.

One notable event of his reign were attacks on the shrines of Ali bin Abu Talib in Najaf, Iraq and on the shrine of Imam Husayn in Karbala, Iraq. This was done in 1802, and is not surprising considering the view in Wahhabism that opposes the building of shrines and which considers the Shia not to be Muslim (both shrines are very important to the Shia).