Andrew P. Sidamon-Eristoff (born February 20, 1963) is an American Republican Party lawyer, politician and government official from New York City who served as New Jersey State Treasurer under Governor Chris Christie from January 2010 until his resignation in July 2015.

His older brother Simon Sidamon-Eristoff is on the board of many charitable and non-profit organizations and Of Counsel to Washington DC–based Firm, Kalbian Hagerty LLP, where he specializes all aspects of doing business as a charity.

On his father's side, Eristoff is a grandson of Prince Simon Sidamon-Eristoff (1891–1961), a Georgian military officer and a scion of the noble Sidamoni-Eristavi family, who emigrated to the United States after the Bolsheviks invaded Georgia in 1921, and married Anne Tracy, a descendant of John Bigelow, an American lawyer, editor and diplomat in the mid-19th century.

[4] Eristoff served as a member of the New York City Council from 1993 until 1999, elected three times to represent an overwhelmingly Democratic district on Manhattan's East Side.

He served in that role until 2002, earning recognition for implementing management strategies that leveraged technology and performance measurement to reduce costs, increase collections, and improve customer service.

In addition to managing the development and execution of New Jersey's $30 billion-plus annual budget, Eristoff played a major role in developing Governor Christie's landmark 2001 pension and health benefits reforms, designed and implemented Governor Christie's Performance Budgeting Initiative, drafted Governor's Christie's $2.3 billion business tax reduction package of 2011, advanced significant procurement process reforms, managed several major privatization initiatives, restructured the State's IT governance configuration, and oversaw debt and financial management reforms that achieved $1.9 billion in budget savings and eliminated the State's exposure to $4.2 billion in risky derivatives.