Mukesh Dhirubhai Ambani was born on 19 April 1957 in the British Crown colony of Aden (in present-day Yemen) to Dhirubhai Ambani and Kokilaben Ambani. He has a younger brother Anil Ambani and two sisters, Nina Bhadrashyam Kothari and Dipti Dattaraj Salgaocar.

Ambani lived only briefly in Yemen because his father decided to move back to India in 1958 to start a trading business that focused on spices and textiles. The latter was originally named “Vimal” but later changed to “Only Vimal.” His family lived in a modest two-bedroom apartment in Bhuleshwar, Mumbai until the 1970s. The family’s financial status slightly improved when they moved to India but Ambani still lived in a communal society, used public transportation, and never received an allowance. Dhirubhai later purchased a 14-floor apartment block called ‘Sea Wind’ in Colaba, where, until recently, Ambani and his brother lived with their families on different floors.

Ambani later enrolled for an MBA at Stanford University but withdrew in 1980 to help his father build Reliance, which at the time was still a small but fast-growing enterprise. His father felt that real-life skills were harnessed through experiences and not by sitting in a classroom, so he called his son back to India from Stanford to take command of a yarn manufacturing project in his company.

In 1980, the Indian government under Indira Gandhi opened PFY (polyester filament yarn) manufacturing to the private sector. Dhirubhai Ambani applied for a license to set up a PFY manufacturing plant. Obtaining the license was a long-drawn-out process requiring a strong connection within the bureaucracy system because the government, at the time, was restricting large-scale manufacturing, making the importation of yarn for the textiles impossible. In spite of stiff competition from Tatas, Birlas and 43 others, Dhirubhai was awarded the license, more commonly addressed as License Raj. To help him build the PFY plant, Dhirubhai pulled his eldest son out of Stanford, where he was studying for his MBA, to work with him in the company. Ambani did not return to his university program, leading Reliance’s backward integration, where companies own their suppliers to generate more revenue and improve efficiency, in 1981 from textiles into polyester fibers and further into petrochemicals, which the yarns were made from. After joining the company, he reported daily to Rasikbhai Meswani, then executive director. The company was being built from scratch with the principle of everybody contributing to the business and not heavily depend on selected individuals. Dhirubhai treated him as a business partner allowing him the freedom to contribute even with little experience. This principle came into play after Rasikbhai’s death in 1985 along with Dhirubhai suffering a stroke in 1986 when all the responsibility shifted to Ambani and his brother. Mukesh Ambani set up Reliance Infocomm Limited (now Reliance Communications Limited), which was focused on information and communications technology initiatives. At the age of 24, Ambani was given charge of the construction of Patalganga petrochemical plant when the company was heavily investing in oil refinery and petrochemicals.

In 1981 he started to help his father Dhirubhai Ambani run their family business, Reliance Industries Limited. By this time, it had already expanded so that it also dealt in refining and petrochemicals. The business also included products and services in retail and telecommunications industries. Reliance Retail Ltd., another subsidiary, is also the largest retailer in India. Reliance’s Jio has earned a top-five spot in the country’s telecommunication services since its public launch on 5 September 2016.

He married Nita Ambani in 1985 and they have two sons; Anant and Akash, and a daughter, Isha. They met after his father attended a dance performance which Nita took part in and thought of the idea of arranging a marriage between the two.

On 6 July 2002, Mukesh’s father died after suffering a second stroke, which elevated tensions between the brothers as Dhirubhai had not left a will for the distribution of the empire in 2004. Their mother intervened to stop the feud, splitting the company into two, Ambani receiving control of Reliance Industries Limited and Indian Petrochemicals Corporation Limited, which was later approved by the Bombay High Court in December 2005.

In 2007, Ambani gifted his wife a $60 million Airbus A319 for her 44th birthday. The Airbus, which has a capacity of 180 passengers, has been custom-fitted to include a living room, bedroom, satellite television, WiFi, sky bar, Jacuzzi, and an office.

Ambani was titled “The World’s Richest Sports Team Owner” after his purchase of the IPL cricket team Mumbai Indians for $111.9 million in 2008.

Ambani directed and led the creation of the world’s largest grassroots petroleum refinery at Jamnagar, India, which had the capacity to produce 660,000 barrels per day (33 million tonnes per year) in 2010, integrated with petrochemicals, power generation, port, and related infrastructure. In December 2013 Ambani announced, at the Progressive Punjab Summit in Mohali, the possibility of a “collaborative venture” with Bharti Airtel in setting up digital infrastructure for the 4G network in India. On 18 June 2014, Mukesh Ambani, while addressing the 40th AGM of Reliance Industries, said he will invest Rs 1.8 trillion (short scale) across businesses in the next three years and launch 4G broadband services in 2015. In February 2016, Ambani-led Jio launched its own 4G smartphone brand named LYF. In June 2016, it was India’s third-largest-selling mobile phone brand. The release of the service Reliance Jio Infocomm Limited, commonly known as Jio, in September 2016 was a success, and Reliance’s shares increased. During the 40th annual general meeting of RIL, he announced bonus shares in the ratio of 1:1 which is the country’s largest bonus issue in India, and announced the Jio Phone at an effective price of ₹0. As of February 2018, Bloomberg’s “Robin Hood Index” estimated that Ambani’s personal wealth was enough to fund the operations of the Indian federal government for 20 days.

Through Reliance, he also owns the Indian Premier League franchise Mumbai Indians and is the founder of Indian Super League, a football league in India. In 2012, Forbes named him one of the richest sports owners in the world. He resides at the Antilia Building, one of the world’s most expensive private residences with its value reaching $1 billion.

In February 2014, a First Information Report (FIR) alleging criminal offenses was filed against Mukesh Ambani for alleged irregularities in the pricing of natural gas from the KG basin. Arvind Kejriwal, who had a short stint as Delhi’s chief minister and had ordered the FIR, has accused various political parties of being silent on the gas price issue. Kejriwal has asked both Rahul Gandhi and Narendra Modi to clear their stand on the gas pricing issue. Kejriwal has alleged that the Centre allowed the price of gas to be inflated to eight dollars a unit though Mukesh Ambani’s company spends only one dollar to produce a unit, which meant a loss of Rs. 540 billion to the country annually.

As of 2016, Ambani was ranked 38 and has consistently held the title of India’s richest person on Forbes magazine’s list for the past ten years. He is the only Indian businessman on Forbes’ list of the world’s most powerful people. As of October 2020, Mukesh Ambani was ranked by Forbes as the 6th-wealthiest person in the world. He surpassed Jack Ma, executive chairman of Alibaba Group, to become Asia’s richest person with a net worth of $44.3 billion in July 2018. He is also the wealthiest person in the world outside North America and Europe. As of 2015, Ambani ranked fifth among India’s philanthropists, according to China’s Hurun Research Institute. He was appointed as a Director of Bank of America and became the first non-American to be on its board.

In an interview with Rajdeep Sardesai in March 2017, he said that his favourite food continued to be idli sambar and his favourite restaurant remains Mysore Café, a restaurant in King’s Circle (Mumbai) where he used to eat as a student at UDCT. Mukesh Ambani is a strict vegetarian and teetotaler. He is a very big fan of Bollywood movies, watching three a week because he says “you need some amount of escapism in life.”

In early 2019, a court in Mumbai held his younger brother, Anil Ambani, in criminal contempt for non-payment of personally guaranteed debt Reliance Communications owed to Swedish gearmaker Ericsson. Instead of jail time, the court gave Anil a month to come up with the funds. At the end of the month, Mukesh bailed out his younger brother, paying the debt.