Dato' Onn Hafiz bin Dato' Ghazi (Jawi: عون حفيظ بن غازي; born 2 March 1979) is a Malaysian politician who has served as the 19th Menteri Besar of Johor and Member of the Johor State Legislative Assembly (MLA) for Machap since March 2022.^[1] He previously served as MLA for Layang-Layang from May 2018 to March 2022. From March 2020 to his promotion to Menteri Besarship in March 2022, he served as Member of the Johor State Executive Council (EXCO) in the Barisan Nasional (BN) state administration under former Menteri Besar Hasni Mohammad. ^[2] He is a member of the United Malays National Organisation (UMNO), a component party of the BN coalition. He has also served as the State Chairman of BN and UMNO of Johor since February 2024 and December 2023 respectively.

Onn Hafiz was born in Simpang Renggam, Kluang, Johor to Dato' Ghazi Ishak (1948–2021) and Datin Roquaiya Hanim Hussein (1949–2005), Hussein Onn's eldest child.^[3][4] He is the great-great-grandson of first and former Menteri Besar of Johor Jaafar Muhammad, great-grandson of seventh and former Menteri Besar of Johor, first and former President of UMNO Onn Jaafar, grandson of third and former Prime Minister of Malaysia Hussein Onn, and nephew of former Minister of Defence Hishammuddin Hussein.

Onn Hafiz went to Royal Military College. He received Bachelor of Arts (BA) in Accounting from University of Hertfordshire.

Onn Hafiz was an EXCO of the UMNO Youth in 2013-2018 under the leadership of Khairy Jamaluddin. In the 2018 election, he was chosen as the candidate for the Layang-Layang^[5] seat and won it with a small majority of only 364 against candidates from PKR and PAS. In the 2022 election, Onn Hafiz switched constituencies to Machap and won it with a majority of 6,543 against 3 candidates including a candidate from PEJUANG, Shahruddin Md Salleh.^[6]

On 15 March 2022, Onn Hafiz was officially sworn in as the new and 19th Menteri Besar of Johor, the 4th officeholder in just a single term of parliament of malaysia. Initially after the 2022 Johor state election, BN Chairman and UMNO President Ahmad Zahid Hamidi revealed that he would submit the name of his predecessor and caretaker menteri besar Hasni Mohammad to Sultan of Johor for Hasni to be reappointed to the position after BN gained landslide victory in the election. BN previously also picked Hasni as its menteri besar candidate before BN returned to power. However a day before his appointment, Hasni suddenly announced his withdrawal from the running for the position and that he would pave way and endorse a younger candidate to lead the state government citing long term development for Johor and Onn Hafiz was instead appointed the next day.

•  Federal Territory (Malaysia) :
  • Commander of the Order of the Territorial Crown (PMW) – Datuk (2018)^[11]
•  Johor :
  • Grand Knight of the Order of Sultan Ibrahim of Johor (SMIJ) – Dato' (2023)^[12]