| Tengku Muhammad Ismail Malay: {{Script|Arab|تڠكو محمد إسماعيل | |
| Yang di-Pertuan Muda of Terengganu | |
| Succession: | Crown Prince of Terengganu |
| Reign: | 12 January 2006 – present |
| Reign-Type: | Tenure |
| Coronation: | 12 January 2006 |
| Cor-Type: | Proclamation |
| Predecessor: | Tengku Mizan Zainal Abidin |
| Birth Name: | Tengku Muhammad Ismail bin Tengku Mizan Zainal Abidin |
| Birth Date: | 1 March 1998 |
| Birth Place: | Kuala Terengganu, Terengganu, Malaysia |
| Regnal Name: | Tengku Muhammad Ismail ibni Al-Wathiqu Billah Sultan Mizan Zainal Abidin |
| Father: | Sultan Mizan Zainal Abidin |
| Mother: | Sultanah Nur Zahirah |
| Religion: | Sunni Islam |
Tengku Muhammad Ismail ibni Al-Wathiqu Billah Sultan Mizan Zainal Abidin (Jawi: تڠكو محمد إسماعيل ابن الواثق بالله سلطان ميزان زين العابدين; born 1 March 1998) is a member of the Terengganu royal family who is the Yang di-Pertuan Muda (Crown Prince) of Terengganu and heir apparent to the Terengganu throne. He is the eldest son of Sultan Mizan Zainal Abidin. He was the Regent of Terengganu when his father reigned as the 13th Yang di-Pertuan Agong of Malaysia from 2006 to 2011.
Tengku Muhammad Ismail was born on 1 March 1998 as the eldest son and second child of Tengku Mizan Zainal Abidin, the then Yang di-Pertuan Muda (Crown Prince) of Terengganu and To’ Puan Seri Rozita binti Adil Bakeri.[1] His father became the Sultan of Terengganu shortly after his birth, after which his mother became known as Permaisuri Nur Zahirah (née Rozita binti Adil Bakeri), the Permaisuri of Terengganu.
He was educated at Garden International School in Kuala Lumpur. He continued his studies in the United Kingdom.
He was appointed as the Yang di-Pertuan Muda (Crown Prince) of Terengganu on 12 January 2006.[2]
After Sultan Mizan was elected as Yang di-Pertuan Agong, he appointed Tengku Muhammad Ismail, then aged eight, as Regent of Terengganu on 12 November 2006.[3] Because of Tengku Muhammad Ismail's young age, a Regency Advisory Council was established to discharge his duties for him. The council's members were Tengku Baderulzaman, Sultan Mizan's younger brother, Tengku Sulaiman Sultan Ismail, Sultan Mizan's uncle, and Federal Court judge Abdul Kadir Sulaiman. He was proclaimed as regent during a ceremony on 12 December.[4]
As regent, he presided over the swearing in of Menteri Besar Ahmad Said following the 2008 general election.[5]
On 26 August 2010, upon reaching age 12 (baligh, the Islamic age of puberty), Tengku Muhammad Ismail was formally proclaimed as Regent during a ceremony at Istana Maziah. A Regency Representative Council was formed to discharge his duties as regent while he left the country to pursue his studies. The council consisted of Sultan Mizan's brother Tengku Mustaffa Kamel, and previous members of the Regency Advisory Council, Tengku Sulaiman and Abdul Kadir Sulaiman.[6]
Like his father, Tengku Muhammad Ismail is an equestrian, and has participated in international events. In June 2010, he finished in second place in the 90 km race at the RTES/D'Armor French Open in Corlay.[7]