Returning from college, Tunney moved into the Lakeview neighborhood. Hearing that Ann Sather was retiring and closing her restaurant in Lakeview in 1981, Tunney met with Sather, offering a proposal to purchase her business. Tunney gained full ownership of the Ann Sather Restaurant and expanded it into a successful local chain. Tunney joined several prestigious entrepreneurial circles and became chairman of the Illinois Restaurant Association. He founded and led the Lakeview Center Business Association and White Crane Wellness Center. As a result of his success, Tunney was inducted into the Chicago Gay and Lesbian Hall of Fame in 1995.
Public service
Tunney opened his restaurants to grassroots and nonprofit organizations as town halls, serving as free meeting places. He committed himself to helping people with HIV and AIDS through programs he created, adopted by the Illinois Masonic Hospital. With a growing business network, Tunney became a fundraiser for local gay and lesbian political advocacy groups. Tunney chaired the small business subcommittee of the Chicago Economic Development Committee. Mayor Richard M. Daley appointed Tunney to the mayor's Parking Task Force.
Alderman
In 2002, just months before the 2003 municipal elections, 44th Ward Alderman Bernie Hansen announced that he would retire. Hansen resigned just months before the election so as to allow the mayor to appoint the replacement alderman. Mayor Richard M. Daley, with Hansen's consent, nominated Tunney to replace Hansen in December 2002. Tunney's nomination was confirmed by a 41–0 vote of the city council on January 16, 2003, and, with wide support in the Democratic Party, Tunney was elected to a four-year term as alderman on February 25, 2003. He has been re-elected four times, in 2007, 2011, 2015, and 2019. During his campaign Tunney claimed that he would address the potential conflict of interest which would arise through his business arrangements by selling his interest in four restaurants. After being elected and sworn in, Tunney decided not to sell. Tunney introduced an ordinance repealing Chicago's ban on foie gras in July 2007 and spearheaded passage of the repeal on May 14, 2008. Tunney considered running for mayor in 2011, but ultimately did not. In 2013, Tunney denied unattributed published reports that he supported moving or demolish the iconic scoreboard at Wrigley Field to clear the view for nearby rooftops owners. Tunney has had an often adversarial relationship with the Ricketts family, current owners of the Chicago Cubs, whose stadium, Wrigley Field, is located in his ward. The Ricketts family has accused Tunney of being, "needlessly disrespectful" in negotiations with them about the redevelopment of Wrigley Field. Cubs chairman Thomas S. Ricketts has publicly criticized Tunney. Tunney considered running for mayor in 2019, but ultimately did not. In the runoff of the election, Tunney endorsed Lori Lightfoot. On May 17, three days prior to her inauguration as mayor, Lightfoot tapped Tunney to serve as both Vice Mayor and Chairman of the Council's Committee on Zoning, Landmarks and Building Standards. On May 29, 2019, Tunney was formally appointed as Chairman of the Council's Committee on Zoning, Landmarks and Building Standards.
Personal life
Tunney is the cousin of Robin Tunney, who played Agent Lisbon on The Mentalist. Tunney was the first openly gay Chicago Alderman.