Kathleen Welch is a principal at Corridor Partners, a left-of-center political advocacy and strategy investment firm that focuses on energy and environment issues.
A 2013 HuffPost article described Welch as “a highly influential figure in Democratic fundraising circles, playing a central role in steering money to environmental and climate coalitions.” In the same piece, Welch is said to have been a “key player in Clean Energy Works, a massive green coalition that blew through tens of millions of dollars in a failed attempt to push climate change legislation.” 
Kathleen Welch graduated with honors from St. Lawrence University in 1981 and also attended the University of Buffalo Law School.  She serves on the board of trustees of St. Lawrence University. 
Welch lives in Washington, D.C., with her wife, Shelley Hearne.  Welch and Hearne met while working at the Pew Charitable Trusts.  Hearne is a public health doctor and senior advisor of CityHealth, a public health initiative sponsored by the de Beaumont Foundation and Kaiser Permanente. 
Welch also works at the Fund for a Better Future, a left-of-center grantmaking organization that sponsors lobbying and social welfare nonprofits in the United States.  She also works at the Shared Ascent Fund, an economic, racial, and gender justice nonprofit. 
Welch previously served as managing program counsel in the Office of Program Operations at the Legal Services Corporation, a federal government-created and funded nonprofit which distributes federal money to regional nonprofits across the United States to provide legal aid to low-income individuals. Despite a founding obligation to remain politically neutral, the LSC has been accused of left-of-center political bias since its establishment, and President Donald Trump has called for its elimination. 
Welch was on the steering committee of the October 2011 Change of Atmosphere Conference, sponsored by EcoAmerica, an environmentalist nonprofit whose goal is to train and educate potential environmentalist leaders. 
Welch was the executive director of Equal Justice Works, a left-progressive advocacy organization that focuses on careers for lawyers. Equal Justice Works was founded in 1986 as the National Association for Public Interest Law to train public interest lawyers and provide legal assistance to the poor and other marginalized communities. 
In 1995, Welch was awarded the Scales of Justice Award by Equal Justice Works, recognizing her commitment to public service and her passion for equal justice.  Past honorees include former Secretary of State Hillary Clinton and Supreme Court Associate Justice Elena Kagan. 
Welch sits on the board of directors of the Natural Resources Defense Council (NRDC), one of the nation’s largest and most active environmentalist groups. Welch is also on the board of the Natural Resources Defense Council Action Fund, the NRDC’s political arm which supports environmentalist candidates and legislation, including the Green New Deal.
Welch is affiliated with Democracy Alliance, a network of highly influential funders within the Democratic Party and the political Left. In 2016, Welch co-sponsored a panel entitled “Climate Can Help Us Win in 2016,” at the Democracy Alliance Spring Investment Conference. Other sponsors included hedge-fund billionaire turned climate-change activist Tom Steyer, the Rockefeller Family Fund, and the Solidago Foundation. 
During the 2020 election cycle, Kathleen Welch has given thousands of dollars to Joe Biden for President and to various Democratic candidates for the U.S. Senate.  During the 2016 presidential election, Welch gave thousands to Hillary for America and the Hillary Victory Fund. 
Welch has also given to ActBlue, an online clearinghouse affiliated with the Democratic Party, and to Democracy Engine, a left-leaning fundraising platform that primarily caters to Democratic Party politicians.