Cruz introduced former technology executive Carly Fiorina, his pick for vice president, at a rally in Indianapolis Wednesday.
The announcement comes the day after Cruz lost five states to GOP front-runner Donald Trump.
The 61-year-old Fiorina previously served as the chief executive of Hewlett-Packard, but has never held elected office. She was the only woman in the GOP's crowded presidential field before dropping out of the race earlier in the year.
Cruz says Fiorina excelled in the "hard-scrabble" male-dominated business world.
