Tim Smith is the director of ESG (environmental, social, and governance) shareholder engagement at Boston Trust Walden which was formerly known as Walden Asset Management. Smith works to promote left-of-center policies on the environment and social issues at private businesses in which his firm invests. Smith and his firm tries to use shareholder advocacy, public policy advocacy, and proxy voting among other issues to advance more left-wing views within private companies; among his campaigns was an effort to pressure companies to withdraw support from the free-market center-right state policy group American Legislative Exchange Council (ALEC).
Smith has become one of the most well-known left-wing ESG advocates in the field. He has been involved with ESG related issues for almost 50 years.
Tim Smith was born in Toronto, Canada and received his BA degree at the University of Toronto. He left Toronto and immigrated to the United States after college, entering theology school. He graduated with a masters of divinity degree from the Union Theological Seminary. 
After college, he became involved in the movement to overturn apartheid racial segregation in South Africa. The movement urged businesses and banks that were doing business in South Africa to withdraw from the country. 
Smith later joined the Interfaith Center on Corporate Responsibility (ICCR). ICCR coordinates corporate responsibility programs for over 300 religious and institutional investors. Smith would work his way up the ladder at ICCR, eventually becoming executive director in 1976. He would lead the group as executive director until 2000, when he left to join Walden Asset Management. 
Walden Asset Management
Smith represents the interests of his clients who choose to invest with his company. Among the issues Smith works on is corporate governance. Some of his clients demand a separation of the roles of chairman and CEO. Some of his clients also demand a say in how much the CEO is paid by the company. Some clients also demand that corporate boards are made up of diverse and independent directors. 
Lobbying and Advocacy Disclosure
Among the things that Smith works is urging corporations to disclose their lobbying practices. In 2012, Smith brought shareholder resolutions demanding increased disclosure of lobbying practices from 3M, ConocoPhillips, UPS, and Devon Energy. While none of the shareholder resolutions passed, they did draw some support from other shareholders. Smith brought similar resolutions against Johnson and Johnson and Target, but he withdrew them after both companies agreed to disclose their practices. 
Campaigns against ALEC
Smith and a number of other far-left activists unleashed a pressure campaign against the free market advocacy group American Legislative Exchange Council (ALEC) after the controversial self-defense shooting of Trayvon Martin by a civilian in 2012, was in the spotlight. ALEC had supported Florida’s “Stand Your Ground” self-defense law that was (in the view of 2nd Amendment supporters, wrongly) implicated in Martin’s death by left-wing supporters of gun control. 
Much of Smith’s work now involves working with companies to support environmentalist combat climate change. He has filed shareholder resolutions to force companies to address aspects of climate change. 
Smith has also been critical of the investment firm Blackrock and its stance on climate change. In 2019, he said that the firm only votes against management around 10% of the time on the issue.