The original Dexter series contains 96 episodes across its eight seasons. Each season has 12 episodes, so the total is 8 × 12 = 96.
The series premiered on Showtime on October 1, 2006, and followed Dexter Morgan, a Miami Metro blood-spatter analyst who secretly hunts murderers. Its original run ended with the eighth-season finale on September 22, 2013. The consistent 12-episode structure makes the total easy to calculate, but viewers sometimes remember different numbers because Dexter later expanded into additional series.
The count of 96 refers specifically to the original Dexter series, not the entire franchise. Dexter: New Blood was a separate limited-series continuation that aired in 2021–2022, while later prequel and sequel projects are also distinct productions. Those episodes should not be added when a question explicitly says “the original Dexter series” and “all 8 seasons.” Another common error is counting seasons rather than episodes, or assuming the finale season had a different number of installments because its story was divided among several major arcs.