Sheehan graduated from Albany Law School.
Prior to being elected mayor, Sheehan was city treasurer. On September 10, 2013, she defeated Corey Ellis in the Democratic primary for mayor of Albany. He went on to build a successful career in the insurance business and together they raised six children.
She started her legal career as an attorney in the Albany office of Bond, Schoeneck & King.
In 1996 she joined Intermagnetics General Corporation, a leading medical device manufacturer based in Latham. As vice president, general counsel and corporate secretary, Kathy helped grow the company from 500 employees to more than 1,200 and from $90 million in sales to more than $300 million.
In 2006, she helped negotiate the $1.3 billion acquisition of Intermagnetics by its largest customer, Philips Medical Systems. Many Intermagnetics employees lost their jobs as a result of the buyout.
In 2009, Sheehan was elected as the city treasurer in Albany, New York, taking office in 2010.
As city treasurer, Sheehan was responsible for increasing parking tickets from $15 to $65 in less than four years to make up for decreased tax inflows during the recession. On November 17, 2012, Sheehan announced herself as a candidate for mayor. On September 10, 2013 Sheehan defeated Corey Ellis in the Democratic primary, in preliminary returns with 6,973 votes to Ellis"s 3,074.