Wagner was born in Gary, Indiana. He attended Merrillville High School and then Indiana University, joining Kappa Sigma Fraternity Beta Theta Chapter. He graduated from Indiana University in 1983. He earned a law degree from University of Virginia and then moved to Dallas, Texas where he became a licensed CPA in the State of Texas, and began a legal career with the national firms Akin, Gump, Strauss, Hauer & Feld and Hopkins & Sutter.

In 1995, Wagner launched AudioNet with Mark Cuban, a platform for broadcasting live sporting events and radio stations over the internet. As CEO, Wagner grew the company and expanded its services to include corporate events and Business services. In 1998 Wagner and Cuban changed the name to Broadcast.com and took the company public in the midst of the dot-com boom. The Broadcast.com IPO set an opening-day record, with shares climbing 249% from an offering price of $18 to a closing price of $62.75. In 1999, Wagner and Cuban sold Broadcast.com to Yahoo! for $5.7 billion, making 300 employees millionaires (briefly, on paper) and Wagner and Cuban instant billionaires. Wagner continued to lead the division as Yahoo! Broadcast until May 2000, when he declined an offer to become Yahoo!’s Chief Operating Officer to focus on other interests.

Wagner has his own charitable foundation, the Todd Wagner Foundation. After meeting with Arnold Schwarzenegger, Wagner in 2001 launched his Foundation’s first children’s program, the Dallas chapter of the After-School All-Stars (then called Inner-City Games), a national program championed by Schwarzenegger that provides year-round Technology, academic, Sports and cultural programs for children in the nation's inner cities. The Dallas After-School All-Stars now reaches more than 4,000 children with programs ranging from chess and art classes to golf, running clubs and math competitions.

The Foundation has also provided funding to bring KIPP (Knowledge is Power Program) charter school to Dallas in 2003 and to Wagner's hometown of Gary, Indiana in 2006. KIPP Truth Academy is a program for students to develop knowledge, skills and character.

In 2014, Wagner launched Chideo, a digital platform designed to raise funds and awareness for causes by connecting fans to celebrities through exclusive video content.

Over the next two years, Wagner expanded the concept through the acquisition of online sweepstakes platform Prizeo[1] in June 2015, and online charity auction site Charitybuzz in October 2015.

In 2016, Wagner announced the formation of Charity Network, parent company to Charitybuzz, Prizeo and Chideo, with a mission to help charities transition from analog to digital. The company harnesses the power of Celebrity, Technology and media to raise awareness and funds for some of the world’s toughest challenges.

In March 2017 Wagner’s Charity Network announced the acquisition of Global Philanthropy Group, a philanthropic consulting firm that develops and implements high-impact philanthropic strategies.

Wagner’s philanthropy has earned him several honors including the national First Star “Visionary Award” (2006), the Dallas CASA “Champion of Children” award (2005), the national “Kappa Sigma Man of the Year” award (2003), the Milton P. Levy Jr. Volunteer Award from Dallas' Special Care and Career Services (2008), an honor from the Urban League of Greater Dallas (2003), “Social Entrepreneur of the Year” from Dallas’ Center for Nonprofit Management (2002), and After-School All Stars’ “Man of the Year” (2000).