Topping the list is Stephen Breyer, who is worth at least $6.1 million — and possibly as much as $16 million going into 2016. Breyer's top holdings include stock in publishing company Pearson PLC, as well as property in New Hampshire and the Caribbean island of Nevis.
Justices Ruth Bader Ginsburg, Samuel Alito, Sonia Sotomayor and Elena Kagan are also worth more than a million bucks. (Ginsburg's reported net worth came in just below Roberts' at a minimum of $4.19 million.)
The same is true of their would-be colleague Merrick Garland, who President Barack Obama has nominated to fill the vacancy following the February death of Justice Antonin Scalia. (Scalia's estate is not required to file a financial disclosure on his behalf.)
If confirmed to the Supreme Court, Garland — currently the chief judge of the United States Court of Appeals for the District of Columbia Circuit — would, in fact, become the court's wealthiest member.
Documents released today indicate Garland is worth at least $7.6 million — and possibly as much as $25 million. Among his top assets? A rental property in New York City and several mutual funds.
Justices Anthony Kennedy and Clarence Thomas are the court's paupers — relatively speaking. Both men's minimum estimated net worth was around $600,000 — although each could be worth as much as $1.2 million.
Assets on the forms, which are filed annually, are reported in broad ranges. This makes it impossible to say precisely how much each justice is worth. Judges are also exempt from disclosing the value of their homes, making an accurate calculation even more difficult.
But suffice it to say, none of the Supreme Court justices are facing economic hardship.
The new documents show that the justices of the Supreme Court were a well-traveled bunch during 2015. All eight members of the Supreme Court took at least one trip sponsored by another organization, often law schools or foundations.
Breyer was the most jet-setting justice in 2015, taking 19 trips sponsored by other organizations. Among them: A pair of weeklong jaunts to Paris — one for a book event and speaking engagements, the other for a conference — and three separate trips to London.
Sotomayor's 16 trips placed second among justices, although none were international. Ginsburg, for her part, took eight trips, including one to Seoul, South Korea, for a "legal exchange program" that the Supreme Court of Korea funded. Alito, Kagan and Kennedy also traveled eight times, followed by Thomas with four trips and Roberts with one — to Tokyo.
While a majority of Supreme Court justices did not actively buy or sell individual company's stocks last year — mutual funds are popular among them — Alito, Breyer and Roberts held equities.
Alito reported stock in aerospace and defense giant Boeing Co., Molson Coors Brewing and oil companies ConocoPhillips Co. and Exxon Mobil Corp., among others. Roberts' stock holdings included Time Warner Inc., satellite radio company SiriusXM and tech titans Microsoft Corp. and Hewlett-Packard Co.
Kennedy, long a moderate voice on the high court, is particularly conservative with his investments. For example, he keeps between $500,000 and $1 million in an account at PNC Bank, according to his disclosure.
In addition to their salaries and financial holdings, most of the Supreme Court justices also collected tens of thousands of dollars each from side jobs — such as teaching gigs, speaking fees and book deals.
Alito earned $21,000 teaching at the University of Kentucky and Duke University. And Roberts earned about $13,600 from the University of Tokyo in Japan, for teaching a course in July on historical perspectives of the U.S. Supreme Court.
Meanwhile, Thomas collected more than $27,000 from teaching gigs at three law schools — Creighton University, George Washington University and Brigham Young University. Thomas' wife, Virginia, also reported earning an unspecified salaries from The Daily Caller, a conservative news website, and Liberty Consulting Inc., her own political consulting firm.
Thomas also received a gift worth $6,500 — a bronze bust of abolitionist Frederick Douglass.
More notable is the person making the gift: Dallas real estate mogul and Republican megadonor Harlan Crow.
This story is from the Center for Public Integrity, a nonprofit, nonpartisan investigative media organization in Washington, D.C. Read more of its investigations on the influence of money in politics or follow it on Twitter.