Catherine Austin Fitts, born on December 24, 1950, in Philadelphia, is an American investment banker, former federal housing official and founder of Solari, which publishes the Solari Report newsletter and interview series on money, markets and politics. In UFO and UAP circles she is known for arguing that vast sums move through the federal government outside public accounting, a claim that writers on secret programs cite to explain how hidden projects could be financed.

Fitts earned a history degree from the University of Pennsylvania in 1974 and an MBA from its Wharton School in 1978. At the Wall Street firm Dillon, Read & Co. she worked in public finance, including a 1982 bond sale for the New York subway system backed by rider fares, and in 1986 she became the first woman promoted to managing director in the firm's history. Under President George H. W. Bush she served from 1989 to 1990 as Assistant Secretary of Housing and Urban Development for Housing.

She then founded Hamilton Securities, which won a HUD contract in 1993 to help manage and sell the department's mortgage assets. HUD canceled the contract in 1997 over alleged accounting errors, and the department's inspector general, the FBI and the SEC investigated; Fitts called the inquiry retribution. The investigation closed in 2002, with investigators reporting no evidence of wrongdoing by Fitts or Hamilton. Her later writing turned to government finance, including a 2004 paper, "The Black Budget of the United States," in which she claimed "evidence that a very large proportion of the nation's wealth is being illegally diverted."

In 2017 Fitts and Michigan State University economist Mark Skidmore reviewed federal reports, starting from an inspector general report of $6.5 trillion in unsupported Army accounting adjustments for fiscal 2015, and reported at least $21 trillion in such adjustments at the Defense Department and HUD between 1998 and 2015. The Pentagon announced its first department-wide audit days after Skidmore publicized the work, without saying what prompted it. PolitiFact, citing budget analysts, found that the total double- and triple-counts internal transfers, exceeds the $8.5 trillion the Pentagon spent over that period, and reflects transactions that could not be fully traced or documented rather than money shown to be wasted or spent fraudulently. Fitts has nonetheless described the sum in interviews as stolen.

Fitts's own UFO account concerns the Arlington Institute, a Washington think tank on whose advisory board she served from 1998 to 2000. She has written that its head, John L. Petersen, asked her to help with a Navy strategic plan for a world in which aliens were openly known to live among humans, and offered to let her meet some, which she says she declined. Petersen and board member Joe Firmage denied her version when a researcher asked in 2008, according to an account republished by Joe Murgia, who in July 2026 also disputed Michael Shellenberger's summary that she had been offered a look at alien bodies. Online, her accounting arguments are often paired with Richard Dolan's idea of a breakaway civilization, giving her a prominent place in theories about how a hidden aerospace complex could be funded.