Her appointment was approved by the shareholders at the company Annual General Meeting here earlier in the day.
"Nita has been engaged in several initiatives that have strengthened Reliance, right from building the world-class township and the ecological development at Jamnagar, next-generation office campuses, etc.," said her husband and RIL chairman Mukesh Ambani, welcoming her on board.
She has also designed customer touch points of Reliance Retail, healthcare initiatives, successfully setting up and running institutions like Dhirubhai Ambani International School and Mumbai Indians (the IPL team) and managing Reliance Foundation.
"We are delighted to welcome her to the Board of Reliance Industries as an accomplished individual who will add significant value to Reliance's journey of growth," Mukesh Ambani noted.
In her acceptance remarks, Nita Ambani, 50, said she took the position "with a sense of humility and responsibility".
"RIL has always aimed to better millions of lives and my mission will be to bring speed, scale and social contract to RIL's larger mission. I accept this responsibility as a tribute to millions of RIL stakeholders, as well as to my tireless colleagues at Reliance Foundation," she said.
Her appointment would bring in a rich experience of her sterling combination of business stewardship and societal transformation across sectors within and outside the company, according to sources.
At the RIL's Jamnagar refinery site in Gujarat, she led the ecological development by implementing a biodiversity plan covering 3.2 million trees over 2000 acres and developed a world-class township in the city from scratch, setting new standards of quality of life.
Nita Ambani has led path-breaking initiatives spanning education, health, rural transformation, environmental protection and sports over the past two decades by setting up institutions in the field of education, sports and healthcare in the country through Reliance Foundation and Mumbai Indians.
Her leadership of 13 schools in the Reliance fold, which provide quality education to more than 15,000 students, including the prestigious Dhirubhai Ambani International School, is a testament to her commitment to excellence in academia.
In the health sector, the recently-modernised Sir H.N. Reliance Foundation Hospital & Research Centre exemplies her dedication to create world-class healthcare facilities.
The hospital will soon have state-of-the-art physical infrastructure developed to international standards, latest of clinical technology across core specialities and have a unique connect with the disadvantaged communities in the neighbourhood.
Another major RF initiative is the Drishti programme conceived and spearheaded by her, which is the largest corporate-driven cornea transplant movement and has already supported more than 12,800 surgeries till date. Two years ago, it launched a national fortnightly Hindi newspaper in Braille, which is now available in 19 countries.
Other initiatives include the Bharat-India Jodi in 460 villages in 11 states focusing on empowering marginal farmers, RF-Information Services programmes connecting fisherfolk, farmers and livestock owners with knowledge providers using a technological platform toching over 100,000 in 1,400 villages.