Jamsetji Nusserwanji Tata (3 March 1839 – 19 May 1904) was an Indian industrialist and philanthropist who founded the Tata Group, India's largest conglomerate. He established the city of Jamshedpur.

Born into a Zoroastrian Parsi family of priests in Navsari. Despite that, Tata broke tradition to become the first businessman in his menage, establishing an export trading firm in Mumbai. He graduated from Elphinstone College in Mumbai as a "Green Scholar."

After working in his father's export-trading firm and recognizing opportunities in the cotton industry during a business trip to China, Tata founded a trading company in 1868. He later ventured into the textile industry and established Empress Mill in Nagpur, afterwards purchasing a bankrupt oil mill in Mumbai and converting it into a cotton mill. Tata's innovative strategies and commitment to industrial development in India led him to establish key institutions and companies, including the Taj Mahal Hotel in Mumbai, which was India's first hotel with electricity, and made significant contributions towards the establishment of the Indian Institute of Science, Tata Steel, and Tata Power. He was so influential in the world of industry that Jawaharlal Nehru referred to Tata as a One-Man Planning Commission.

Tata was a philanthropist, particularly in the fields of education and healthcare. His donations and foundations laid the groundwork for modern Indian industry and philanthropy. Tata's legacy includes the city of Jamshedpur, named in his honour, and a lasting influence on India's industrial and social landscape. He married Hirabai Daboo, and their sons, Dorabji Tata and Ratanji Tata, continued his legacy within the Tata Group. Tata's contributions were recognized posthumously, including being ranked first in the "Hurun Philanthropists of the Century" (2021) by total donations of $102.4 billion (in 2021 prices) with the start of his key endowments back in 1892.

Jamshedji Tata was born to Nusserwanji and Jeevanbai Tata on 3 March 1839 in Navsari, a city in southern Gujarat. He was born in a respectable, but poor family of priests. His mother tongue was Gujarati. He broke his family's priestly tradition to become the first member of the family to start a business. He started an export trading firm in Mumbai.

Unlike other Zoroastrians, Jamshedji Tata had a formal Western education because his parents saw that he was gifted in mental arithmetic from a young age. However, for him to have a more modern education, he was later sent to Bombay. He joined his father, Nusserwanji, in Bombay at the age of 14 and enrolled at Elphinstone College, completing his education as a "Green Scholar" (the equivalent of a graduate). He was married to Hirabai Daboo while still a student.

After graduating from the Elphinstone College in 1858, he joined his father's export-trading firm, and helped establish its strong branches in Japan, China, Europe, and the United States. Nusserwanji Tata wanted his son to be a part of this business, so he sent him to China to learn running a business there and the details about the opium trade. However, when Tata travelled around China, he began to realize that the cotton industry was booming and there was an opportunity of making a great profit.

Tata worked in his father's company until he was 29. He founded a trading company in 1868 with ₹21,000 capital (worth US$52 million in 2015 prices). He bought a bankrupt oil mill at Chinchpokli in 1869 and converted it to a cotton mill, which he renamed as Alexandra Mill. He sold the mill 2 years later for a profit. Later, in 1874, Jamshedji Tata floated the Central India Spinning, Weaving, and Manufacturing Company in Nagpur because it seemed like a suitable place for him to establish another business venture. Due to this unconventional location, the people of Bombay scorned Tata for not making the smart move by taking the cotton business up in Bombay, known as the "Cottonopolis" of India. They did not understand why he went to Nagpur to start a new business.