Daniel Santorum is the third child and second son of former U.S. Senator Rick Santorum and author Karen Santorum, born into a prominent conservative Catholic family known for its political involvement and advocacy for traditional values. He is part of a large family of seven siblings: Elizabeth, Richard Jr., Gabriel (who faced severe health challenges as an infant), Patrick, Maria, and Isabella (born with Trisomy 18 in 2008). The family's experiences, including caring for Isabella at home, have been publicly shared by his parents to highlight pro-life stances and family-centric policies.

After completing his education, Daniel pursued a career in finance, establishing himself as a commodities trader based in New York City. He has maintained a lower public profile than his parents but has actively supported Rick Santorum's presidential campaigns in 2012 and 2016, contributing to family political endeavors through volunteer work and embodying the conservative principles central to the Santorum legacy. His professional life in the financial sector reflects a blend of personal ambition and familial loyalty, with no major public controversies or legal issues documented.

As a member of a politically influential family, Daniel's background underscores themes of faith, public service, and economic conservatism, though he has not sought elected office himself.