Delnaaz Irani was born on September 4, 1972, in Mumbai, Maharashtra, India. She is the daughter of Mehelli Irani and Roda Irani and has two brothers, Paurus Irani and Bakhtiyaar Irani. Delnaaz completed her schooling at J.B. Vachan High School in Mumbai and pursued higher education at Jai Hind College. She was married to actor Rajeev Paul from 2005 until their divorce in 2012. Since 2012, she has been in a relationship with Percy Karkaria.

Delnaaz began her acting career in the early 1990s, appearing in Baba Sehgal's music video "Ga Ga Ga Gori Gori." She made her television debut in 1992 with the show "Commander." In 1999, she gained recognition for her role as Kavita Vinod Verma in the sitcom "Yes Boss." Her film debut came in 1999 with "C.I.D.," where she played the role of Bela. She is best known for portraying Jaspreet 'Sweetu' Kapoor in the 2003 film "Kal Ho Naa Ho." Delnaaz has also participated in reality shows like "Nach Baliye" with her then-husband Rajeev Paul and "Bigg Boss 6," where she was evicted on the 93rd day.