Robertson is the son of Julian Hart Robertson Sr., a textile company executive, and the former Blanche Spencer. He graduated from Episcopal High School in 1951 and the University of North Carolina at Chapel Hill in 1955. While at Chapel Hill, he was admitted to Zeta Psi fraternity. He then served as an officer in the U.S. Navy until 1957.

After leaving the Navy, Robertson moved to New York City and worked for a time as a stockbroker for Kidder, Peabody & Co. At Kidder, he eventually headed the firm’s asset management division (Webster Securities) before departing to move with his family to New Zealand for a year to write a novel. On his return, in 1980 Robertson launched Tiger Management with initial investments from friends and family.

On April 1, 1996, BusinessWeek carried a cover story written by reporter Gary Weiss, called “Fall of the Wizard”, that was critical of Robertson’s performance and behavior as founder and manager of Tiger Management. Robertson subsequently sued Weiss and BusinessWeek for $1 billion for defamation. The suit was settled with no money changing hands and BusinessWeek standing by the substance of its reporting.

The Tiger funds reached a peak of $22 billion in assets in 1998. Robertson’s Tiger Fund accurately predicted the Tech Bubble, purposely underweighting the sector due to the overpricing of technology securities in comparison to their earnings and earning potential. So, though Tiger underperformed the S&P 500 in the short term, the fund accurately predicted the underlying flaw in the market. “The proportion invested into technology stocks by Tiger Management, for example, a well-known value-manager, is low. In 1999 Tiger eliminated virtually all investments in this segment. This is consistent with the widely reported refusal of Julian Robertson, manager of the Tiger Fund, to buy into the internet bubble.”

Tiger’s largest equity holding at that time was U.S. Airways, whose troubles dragged down the value of his holdings. Such missteps ultimately led him to close his investment company in March 2000 and return all outside capital to investors. Tiger earlier made $2 billion in gains but then gave most of them back during a huge one-day move in the yen in 1998. In September 2001, Robertson distributed 24.8 million greatly devalued U.S. Airways shares to former Tiger investors. Robertson declared his intent to hold onto his own stock in the airline.

After closing his fund in 2000, Robertson kept his hand in the hedge fund business by supporting and financing upcoming hedge fund managers (38 in total as of September 2009), in return for a stake in their fund management companies. Apart from those, many of the analysts and managers Robertson employed and mentored at Tiger Management, including Chris Shumway, Lee Ainslie and Ole Andreas Halvorsen went out on their own and are now running some of the best-known hedge fund firms, called “Tiger Cubs”. These include funds such as Viking Global Investors, Tiger Legatus, Tiger Veda, Blue Ridge Capital, JAT Capital Management, Tiger Global, Maverick Capital, Coatue Management, Nehal Chopra’s Tiger Ratan Capital Fund NA among others.

In 2008, he was inducted into Institutional Investors Alpha’s Hedge Fund Manager Hall of Fame along with Alfred Jones, Bruce Kovner, David Swensen, George Soros, Jack Nash, James Simons, Kenneth Griffin, Leon Levy, Louis Bacon, Michael Steinhardt, Paul Tudor Jones, Seth Klarman and Steven A. Cohen.

In August 2010, Robertson signed The Giving Pledge, an initiative by software mogul Bill Gates and investor Warren Buffett in which the wealthy would pledge at least half their assets to charity.

He also is active as an investor and developer in New Zealand, where he spends some time. His family owns three lodges: Kauri Cliffs Lodge near Matauri Bay in Northland; Matakauri Lodge Queenstown; and The Farm at Cape Kidnappers, Hawkes Bay, as well as several wineries. Robertson was appointed an Honorary Knight Companion of the New Zealand Order of Merit, for services to business and philanthropy, in the 2010 New Year Honours. In 2009, it was announced that Robertson would donate art valued at $115 million to the Auckland Art Gallery. The donation included works by Paul Cezanne, Paul Gauguin, Pablo Picasso, Henri Matisse, Piet Mondrian, Salvador Dali, Georges Braque, Andre Derain, Fernand Leger, Pierre Bonnard and Henri Fantin-Latour and was the largest of its kind in Australasia.

In May 2010 the New York Stem Cell Foundation, a private research institution, received a $27 million gift from Robertson to fund its research. Josephine Tucker Robertson, wife of Julian Robertson, died 8 June 2010 after a long fight against breast cancer.

In January 2012 Robertson donated $1.25 million to Restore Our Future, a Super PAC supporting Mitt Romney’s presidential campaign. In 2015, Robertson gave $1 million to a Super PAC supporting Jeb Bush’s presidential candidacy. In April 2016, Robertson gave $25M to Success Academy Charter Schools in New York.

At September 2020 around 50% of his investments were in the technology sector, with the largest investments being in JD.com, Microsoft, Facebook and Amazon.