Thomas Secunda was born in 1954 in Bethpage, New York. He graduated from Binghamton University with Bachelor's and Master's Degrees in mathematics.

In 1982, Secunda joined his former Salomon Brothers colleagues Michael Bloomberg, Duncan MacMillan, and Charles Zegar to set up Innovative Market Systems, later renamed Bloomberg L.P. in 1987. He serves as the global head of Bloomberg’s Financial Products and Services where his primary responsibility is to help Bloomberg develop new features and tools for the Bloomberg Professional Service, the company’s primary product, driving 85 percent of its estimated $7 billion in revenue. As head of Financial Products, Secunda oversees a global staff of 6,000. In July 2011, Secunda was appointed vice chairman of Bloomberg L.P. following Daniel L. Doctoroff's promotion to CEO.

Secunda and his wife Cindy are signatories of the Giving Pledge. The beneficiaries of the couple's charitable giving are primarily organizations that focus on "National Parks, local parks, conservation, Health care and Jewish causes." He supports the American Israel Education Foundation, the American Jewish Joint Distribution Committee, and the UJA Federation. In 2011, Secunda was appointed Chairman of the Board of Directors for the National Parks Conservation Association. He also serves on the board of trustees for the Intrepid Museum Foundation, and on the board of Directors of the Manhattan Theater Club.In 2012, he was awarded the Simon Wiesenthal Center's award for his philanthropic work.