Mexico's Carlos Slim Helu and his family were still the wealthiest on the globe with a net worth of $73 billion.
The telecommunications mogul has topped Forbes' annual list of the world's richest people for the past four years.
Like all those on this year's list that were reachable Monday, Simons, 74, declined through an aide to comment.
The United States continued to be home to more billionaires than anywhere else, 442 in all. But some well-known names did not fare as well as in past years.
New York Mayor Michael Bloomberg, whose fortune is derived from the Bloomberg financial information service, climbed seven spots to No. 13. His net worth was $27 billion, a gain of $5 billion year over year.
Asked about his ranking, Bloomberg said Monday, "Look, the numbers in these things are always suspect. And I never liked any of these lists."
Besides Simons, the other Long Islanders on the list, based on voter registration and land records, were:
Charles Dolan, 86, at No. 437; he and his family had a net worth of $3.1 billion. The Cove Neck resident founded Cablevision Systems Corp., which owns Newsday.
Julian Robertson Jr., 81, a hedge fund investor from Locust Valley, was No. 503 with $2.8 billion.
Marc Rowan, 51, an investor from Southampton, was No. 704 with $2.1 billion.
Kenneth Langone, 77, was No. 792 with $1.9 billion. The Sands Point resident helped start the building supply retailer Home Depot.
Louis Bacon, 54, was No. 1,107 with $1.3 billion. The hedge fund investor owns property in Oyster Bay and helped preserve much of Peconic Bay's Robins Island.