The second season will consist of 10 episodes -- up two from the show's freshman season. Season 2 will begin production later this year in Dublin for a 2015 premiere.
"Penny Dreadful," starring Eva Green, Timothy Dalton and Josh Hartnett, features a roster of classic monsters such as Frankenstein, Dorian Gray and Dracula. Screenwriter John Logan created the series and is writing every episode, which imagines a world in which the creatures walk the streets of Victorian-era London.
The series debuted in May to 872,000 first run viewers in its Sunday night time slot -- topping the premieres of "Homeland" and "Masters of Sex" -- and increased to 1.44 million viewers for the night when including encores. It was also the cable network's youngest-skewing premiere since the debut of "Dexter" in 2006, with 62 percent of the audience coming from the coveted 18-49 demo.
Showtime also says that "Penny Dreadful" is its most-watched new show ever on Showtime on Demand and Showtime Anytime, with more than 3.6 million viewers through three weeks. The series is currently averaging 4.8 weekly viewers across multiple platforms.
"The show has been an interesting combination of genre credibility -- it is simultaneously a gorgeous historical costume drama and a really scary, twisted horror show," said Showtime president David Nevins. "The question was, could we do a genre show that made sense on Showtime that had adult appeal and the psychological sophistication you expect from one of our premium dramas, but still satisfies drama audiences. John Logan has delivered on both. We're looking at this as a big-time franchise to grow over time and the show is only just beginning to lay out the world of 'Penny Dreadful.'"
The next drama to debut on the premium cable network will be "The Affair, starring Josh Jackson, Ruth Wilson, Maura Tierney and Dominic West, premiering in the fall, while new comedy "Happyish" has been put on pause due to the death of star Phillip Seymour Hoffman.
Showtime's drama slate currently includes "Homeland," "Masters of Sex" and "Ray Donovan," plus dramedy "Shameless," while its comedies include "Nurse Jackie," "Episodes," "House of Lies" and "Web Therapy."
"Penny Dreadful" continues Sundays at 10/9 p.m. CT on Showtime.