Serving as the State Mufti of Brunei since 1994, his appointment marked a pivotal moment in the country's Islamic governance, aligning with a strengthened focus on state-led Islamisation.

He received his early education in Brunei before continuing his studies at Madrasah Aljunied Al-Islamiah in Singapore in 1955, Kolej Islam Malaya in 1962, and Al-Azhar University in Cairo, where he graduated with a Bachelor of Arts in 1968.

[1][3] The appointment of Abdul Aziz Juned as state mufti on 1 September 1994[4] marked a significant turning point in Brunei's Islamic governance, coinciding with an intensified effort toward state-led Islamisation.

Abdul Aziz, alongside Mahmud Saedon as special advisor in Syariah affairs, emerged as one of the most influential ulama in Brunei's modern history.

During this period, the groundwork for a comprehensive Islamic criminal law code was laid, with Abdul Aziz playing a central role in shaping Brunei's legal and religious framework.

[5] As the head of the Brunei Islamic Religious Council's legal committee, Abdul Aziz Juned played a pivotal role in shaping the country's Syariah reforms.

Brunei's commitment to ensuring the SPCO aligns with established Syariah law principles is further demonstrated by the consultations it held with Islamic organisations in Saudi Arabia, Pakistan, and Aceh.

Despite widespread condemnation from the United Nations, human rights organisations, and prominent figures such as US President Joe Biden, George Clooney, and Elton John, Abdul Aziz maintained that those who viewed the sanctions as harsh had misinterpreted their intent.

[12] In 2015, amid global counter-terrorism efforts, Abdul Aziz condemned ISIS, stressing that Islam forbids bloodshed unless explicitly authorised by Syariah law.