Speed of Darkness is the fifth studio album by the Irish-American Celtic punk band Flogging Molly, released on May 31, 2011.

[2][3] The album was produced by Ryan Hewitt, who has worked with bands Red Hot Chili Peppers and the Avett Brothers.

The expression speed of darkness had appeared in a 1999 book mixing physics and fiction, named The Science of Discworld, written by Terry Pratchett, Ian Stewart and Jack Cohen.

Allmusic gave the album a mostly positive review, commenting that "while Flogging Molly hasn’t done much to innovate on their sound over the past decade or so, it doesn’t feel like they have to."

Spin's reception was more mixed, as they wrote that while "rabble-rousing frontman Dave King champions defiant hope amid crushing desperation" the "overly smooth production undercuts his righteous fury, suggesting the group harbors dreams of a Green Day-style commercial breakthrough."