Benjamin "Ben" Cahill is one of the main antagonists of the first season of Timeless and a supporting protagonist in the series finale "The Miracle of Christmas." In the first season, he threatens Rufus and his family into doing Rittenhouse's dirty work and recording the team's actions. It later turns out he is the biological father of Lucy Preston and an agent of Rittenhouse. Cahill is arrested by Denise Christopher for his activities but helps her find Emma Whitmore and Rittenhouse to save Lucy and granted amnesty for his teenage son. He is also the maternal grandfather of Flynn and Amy Logan and father-in-law of Wyatt Logan.
He is played by .