Justice Andrew J. McDonald is a Connecticut native. Born in Stamford on March 11, 1966, he attended public schools there before entering college. After graduating from Cornell University with a Bachelor of Arts degree in 1988, he earned a Juris Doctor degree, with honors, from the University of Connecticut School of Law in 1991, where he served as the Managing Editor of the Connecticut Journal of International Law. Justice McDonald also holds an honorary Doctor of Laws degree from Western New England University School of Law.

In January of 2013, Governor Dannel P. Malloy nominated Justice McDonald to be an associate justice of the Connecticut Supreme Court, and he was confirmed by the Connecticut General Assembly later that month. He was sworn into office on January 24, 2013. In January of 2021, Governor Ned Lamont re-nominated Justice McDonald to the Supreme Court, and later that month he was again confirmed by the General Assembly.

In addition to his service as an associate justice, Justice McDonald also serves as the Chairman of the Connecticut Criminal Justice Commission and the Chairman of the Rules Committee of the Superior Court. Justice McDonald is the senior associate justice of the Supreme Court.

Prior to his appointment to the Supreme Court, Justice McDonald served as the General Counsel to the Office of the Governor for the State of Connecticut from 2011 to 2013. In this role, he served as chief legal advisor to the Governor, the Lieutenant Governor and senior staff of the Executive Branch of government. His responsibilities included providing legal counsel and analysis on all aspects of Executive Branch functions and operations, including its interactions with the federal government and the Judicial and Legislative branches of state government.
 
From 1991 to 2011, Justice McDonald was engaged in the private practice of law, first as an associate and then as a partner, with the firm of Pullman & Comley, LLC. He was a commercial litigator and handled all stages of litigation in federal and state courts at both the trial and appellate levels.

From January of 1999 to July of 2002, Justice McDonald additionally served as the Director of Legal Affairs and Corporation Counsel for the City of Stamford. In this capacity, he served in the Mayor’s Cabinet and oversaw the administration, supervision and performance of all legal, human resource and labor relations functions of the city, and its boards, commissions and agencies.

Justice McDonald was a State Senator from 2003 to 2011. He served as the Senate Chairman of the Judiciary Committee for all eight years he was in the General Assembly. During periods of his legislative career he also served as the Senate Vice Chairman of the Energy and Technology Committee and as a member of the Finance, Revenue and Bonding Committee, the Transportation Committee, the Education Committee and the Regulations Review Committee. From 2005 to 2011, he served as Deputy Majority Leader of the Senate.

Earlier in his career, Justice McDonald served on the Stamford Board of Finance from 1995 to 1999, including serving as the board's Chairman from 1997 to 1999, and as Co-Chair of the Audit Committee from 1995 to 1997. He began his public service career in 1993 as a member of the Stamford Board of Representatives, where he served until 1995.

Justice McDonald and his husband, Charles, live in Hartford.