Firoz and Zahan Mistry, sons of the late Cyrus Mistry, are the richest billionaires at age 30 and under, according to 2024 Forbes Billionaires List. With a net worth of $4.9 billion each, they are also among the world's youngest billionaires. Firoz (aged 27) and Zahan (25) inherited 4.6% stakes in Tata Sons after Cyrus died in a car accident.