The Spanish Inquisition prosecuted about 150,000 people over the course of its history.
That figure is an estimate of prosecutions or cases handled, not a count of people executed. The tribunal investigated a wide range of alleged religious offenses, with its priorities changing over time. Early campaigns focused heavily on conversos—Christians of Jewish ancestry suspected of secretly practicing Judaism—and later attention also included Moriscos, Protestants, blasphemers, bigamists, and other offenders.
The total is difficult to calculate because records are incomplete and surviving documentation varies by tribunal and period. The Suprema, the central governing council, preserved substantial records, but important gaps remain, especially for local courts and earlier decades. Historians therefore present the number as an approximation rather than an exact census.
A common misconception is that everyone prosecuted was executed. Most received other penalties, such as penance, public flogging, exile, imprisonment, confiscation of property, or service in the galleys. Estimated executions were only a small fraction of the roughly 150,000 prosecutions.