Abdul Halim's maternal grandfather, Tunku Mahmud, was once Raja Muda (heir presumptive) to the throne of Kedah.

He subsequently joined the Kedah Administrative Service, serving in the Alor Star district office and later, the state treasury.

[3] On 6 August 1949, Abdul Halim was appointed Raja Muda or heir apparent, and acceded as the 28th Sultan of Kedah upon his father's death on 14 July 1958.

[7] A ceremony of handing over the contributions in conjunction with the golden jubilee was held at the Istana Anak Bukit on 6 July 2008 by Kedah Chief Minister Azizan Abdul Razak.

He was the third youngest monarch to ascend the throne of the Yang di-Pertuan Agong after Putra of Perlis and Mizan Zainal Abidin of Terengganu.

[8] On 2 November 2006, Abdul Halim was elected for the second time to serve a five-year term as Deputy Yang di-Pertuan Agong.

Sultan Abdul Halim died at 2:30 pm on 11 September 2017, at the age of 89 (about 2 months ago before his 90th birthday), at the Istana Anak Bukit in Alor Setar.

[13][14] He was laid to rest next to the grave of his late wife, Sultanah Bahiyah at the Langgar Royal Mausoleum in Alor Setar, Kedah on the day after his death.