Nathaniel Charles Jacob Rothschild, 4th Baron Rothschild (29 April 1936 – 26 February 2024), was a British hereditary peer, investment banker and member of the Rothschild banking family. Rothschild held important roles in business and British public life, and was active in charitable and philanthropic areas.

He was the eldest son of Victor Rothschild, 3rd Baron Rothschild. Raised in a background that intertwined Jewish heritage with the tenets of Orthodox Judaism through his mother's conversion, Rothschild's education spanned from Eton College to Christ Church, Oxford, where he performed well in history. His early life was marked by membership of the Bullingdon Club and familial connections, including half-siblings Emma Rothschild and Amschel Rothschild.

Rothschild's business career started at N M Rothschild & Sons in London, though a familial dispute led to his departure in 1980. Despite relinquishing his stake in the family bank, he maintained influence through the Rothschild Investment Trust, now RIT Capital Partners plc, among other ventures. Notable business activities included founding J. Rothschild Assurance Group with Mark Weinberg and participating in high-profile bids and partnerships. His tenure as Deputy Chairman of BSkyB Television and involvement with RHJ International and Blackstone Inc. highlighted Rothschild's diverse business interests, leading to a Commander of the Royal Victorian Order honour in 2020, for services to the Duchy of Cornwall.

Rothschild was married to Serena Mary Dunn, with whom he had four children, continuing the Rothschild legacy. His philanthropic efforts were extensive, chairing and contributing to art and heritage organizations, notably the National Gallery and the Heritage Lottery Fund in the UK. Rothschild's participation in restoring Waddesdon Manor and engagement with the Butrint Foundation in Albania showed his interest to cultural preservation. His chairmanship of Yad Hanadiv reflected his commitment to philanthropy in Israel. Under his leadership, the organization went beyond funding national landmarks and began to focus on education initiatives, environmental pursuits and advancing equal opportunity for Israel's Arab minority.

Born at Merton Hall in Cambridge on 29 April 1936, Nathaniel Charles Jacob Rothschild was the eldest son of Victor Rothschild, 3rd Baron Rothschild, by his first wife Barbara Judith Rothschild (née Hutchinson). His father was born into a Jewish family, while his mother converted to Orthodox Judaism when they married. Rothschild was educated at Eton College and then at Christ Church, Oxford, where he gained a First in history, tutored by Hugh Trevor-Roper. At Oxford he was a member of the Bullingdon Club. Emma Rothschild is his half-sister and Amschel Rothschild was his half-brother.

From 1963, Rothschild worked at the family bank N M Rothschild & Sons in London, before resigning in 1980 due to a family dispute. The chairmanship of the bank had passed from his father, who had chosen to follow a scientific career and had lost control of the majority voting shares, to his distant cousin Sir Evelyn de Rothschild. He sold his minority stake in the bank, but took independent control of Rothschild Investment Trust (now RIT Capital Partners plc), an investment trust listed on the London Stock Exchange.

After resigning from the bank in 1980, Rothschild went on to found J. Rothschild Assurance Group (now St. James's Place plc) with Mark Weinberg in 1991. In 1989, he joined forces with Sir James Goldsmith and Kerry Packer in an unsuccessful bid for British American Tobacco.

Rothschild was Chairman of RIT Capital Partners plc, one of the largest investment trusts quoted on the London Stock Exchange with a net asset value of about £2 billion. He was Chairman of J Rothschild Capital Management, a subsidiary of RIT Capital Partners plc. He also retained many other venture capital and property interests.