His father, Mohd Zainuddin Hj Senawi, was a clerk in the Kedah State Civil Service, while his mother, Pok Rafeah Binti Ishak, was a homemaker.

He later attended Sultan Abdul Hamid College, an English-medium school, and completed his upper secondary education at St. Xavier's Institution, George Town, Penang.

[3] Daim's mother supported his aspirations to study law, selling the family's land to fund his education in the United Kingdom.

[3] In 2019, at the age of 81, Daim obtained a Doctor of Philosophy (PhD) degree from the University of Malaya after completing a thesis on the New Economic Policy[4] which he had worked on for 11 years.

[7] Upon Pakatan Harapan's victory, he was appointed to the newly founded Council of Eminent Persons, which served as an advisory body to the new government.

As part of a broader investigation stemming from the Pandora and Panama Papers which began in 2022, the MACC petitioned Daim to declare his and his family's assets.

[10] Daim and Mahathir, whose son has also been subjected to an anti-corruption probe, had accused the investigators of having political motivations in targeting government critics.

[11] In January 2024, Daim was charged under anti-corruption laws for failing to declare 71 assets, including two investment accounts, six luxury vehicles, 24 properties and plots of land, and 38 companies.