Dhirajlal Hirachand Ambani (; 28 December 1932 – 6 July 2002) was an Indian industrialist who founded Reliance Industries, a petrochemicals, communications, power, and textiles conglomerate and one of the 3 privately owned Indian companies in the Fortune 500. Ambani took his company public in 1977. Dhirubhai has been among the select few to be figured in the Sunday Times list of top 50 businessmen in Asia. His life has often been referred to as a true "rags to riches" story.

Dhirajlal Hirachand Ambani (* 28. Dezember 1932 in Chorwad, Gujarat; † 6. Juli 2002 in Mumbai, Maharashtra) war der Gründer des indischen Petrochemiekonzerns und Indiens reichster Milliardär. Er ist auch unter dem Namen Dhirubhai Ambani bekannt (bhai ist ein respektsbezeugender Suffix in Gujarat und heißt in vielen indischen Sprachen „älterer Bruder“).