Irani was born on 2 December 1959, in Mumbai. He finished his schooling in St. Mary's School, Pune. In a talk in 2014 at the SRCC Youth conference, Irani recounted that at school, he was a quiet child as he used to lisp, and was dyslexic and had ADHD. He got over his lisp eventually. He studied a six months waiter course at Mithibai College in Mumbai. After his polytechnic diploma course, he joined the Taj Mahal Palace & Tower and worked there as a waiter and in room service. He gradually got promoted and finally worked as a waiter at the rooftop French restaurant, Rendezvous. He worked at the Taj Mahal for two years.
While he was at school, he would watch movies daily at the Alexander cinema daily after school. His mother often encouraged him to watch the movies repeatedly, to observe their cinematography and art. Irani's father died three months before Irani was born, but had a farsan making shop, which his mother took over thereafter. Irani also worked at this shop in Grant road till he was 32 years old. This ancestral bakery and farsan shop was located in the Grant road area of Mumbai, between Novelty and Apsara Cinemas, and was also where he first met his wife.
While working at the Taj, using the tips that he received, Irani bought a camera and took sports pictures (school cricket and football matches), selling them for twenty to thirty rupees, which he continued till well after marriage. His epiphany came when he saved money for seven years to take his family for their first ever vacation to Ooty, but they ended up in a desolate run-down hotel, ironically called Shawham palace. Irani decided to take control of his life, and instead of living the petty existence of a photographer selling small photos and making a living, he would start to dream and live big and provide for his family in a better manner. Irani calls it his "zero number bulk moment".
Irani continued to be a photographer, but now at the age of 32, went six months prior to the world boxing championships at Mumbai to meet Adajania, the then president of the Olympic boxing association of India, and requested to become the official photographer of the World Cup. When Adajania told him there was no need for him, Irani offered to work at his office for six months for free in return for a ring-side badge to cover the event. He continued to try to convince Adajania, and covered a state boxing match in a different manner than other photographers. Adajania was impressed by his photos and his passion and appointed Irani as the official photographer.
Meanwhile, he became the photographer for the Norwegian boxing team and photographed specific photos that they needed of Ole_Klemetsen. When asked about his charges, Irani asked for the international rate. Irani took the required photos with his K-1000.
Irani began his acting career in theatre and moved to films in 2000. Irani gained attention for his role in the 2003 comedy Munna Bhai M.B.B.S.. He later appeared in Lage Raho Munna Bhai for which he received several IIFA award nominations and in 3 Idiots opposite Aamir Khan which earned him a Filmfare Award and a Star Screen Award for Best Actor in a Villainous Role.
Acting had been a passion to Irani during school and college days. He trained under acting coach Hansraj Siddhia from 1981 to 1983 and adopted professional acting methods. Irani preferred British theatre, and he soon developed different accents.
Irani's mentor was Alyque Padamsee — the veteran theatre actor best known for his role as Mohammad Ali Jinnah in Gandhi. He was introduced to Padamsee by Shiamak Davar. Irani's earliest theatrical appearance was in Roshni where he played a cameo at the Regional Theatre in Versova. He followed this up with serials like Family Ties and Mahatma vs Gandhi, playing Gandhi after the role was turned down by Darshan Jariwala. His most illustrious play till date has been I am not Bajirao which ran for 10 years.
Irani started out in a number of advertisements such as Fanta, Ceat and Krackjack biscuits (as Mr. Jack of the Krack and Jack duo).
His small but significant role in Darna Mana Hai earned him acclaim. The film didn't fare too well, but his was one of the most remembered segments of the film along with Sanjay Dutt. With Munna Bhai M.B.B.S., Irani became popular. His role as J. Asthana earned him a Filmfare Award nomination for Best Comedian. His comic as well as minor antagonist type role in 3 Idiots is also still remembered. Irani has appeared in many comedic roles (Main Hoon Na, Lage Raho Munna Bhai, Dostana, Khosla Ka Ghosla, Waqt: The Race Against Time, No Entry, Housefull, Ek Main Aur Ekk Tu, Housefull 2 and Cocktail), supporting roles (Veer-Zaara, Maine Gandhi Ko Nahin Mara, Lakshya, Honeymoon Travels Pvt. Ltd., Sorry Bhai!, Page 3, My Wife's Murder), and negative roles (Don: The Chase Begins Again , Don 2: The King Is Back, Eklavya). He acted in his first Telugu film Attharintiki Daaredhi as the grandfather of Pawan Kalyan.
Irani hosted the IIFA Awards with actor Ritesh Deshmukh in 2008 in Bangkok, 2009 in Macau, 2010 in Colombo and 2011 in Toronto. He has been on Kaun Banega Crorepati with Sanjay Dutt. He also hosted the quiz show Bollywood Ka Boss. Irani featured in OneTouch Glucose Meters TV commercials in 2015 with Simone Singh.
Boman Irani is an Irani and follows the religion of Zoroastrianism. He speaks English, Hindi, Gujarati, Bengali and Marathi fluently. Irani is a member of the Parsee Television Actors Community and is its secretary. He is married to Zenobia, with whom he has two sons, Danesh and Kayoze Irani.