The fifth season of the American television series The Flash, which is based on the DC Comics character Barry Allen / Flash, premiered on The CW on October 9, 2018, and concluded on May 14, 2019, with a total of 22 episodes. The season follows Barry dealing with the consequences of his future daughter's time traveling, while confronting a new foe in Orlin Dwyer, the Cicada. It is set in the Arrowverse, sharing continuity with the other television series of the universe, and is a spin-off of Arrow. The season was produced by Berlanti Productions, Warner Bros. Television, and DC Entertainment, with Todd Helbing serving as showrunner.

The Arrowverse is an American superhero media franchise and shared universe that is centered on various interconnected television series based on DC Comics superhero characters, primarily airing on The CW as well as web series on CW Seed. The series were developed by Greg Berlanti, Marc Guggenheim, Andrew Kreisberg, Geoff Johns, Ali Adler, Phil Klemmer, Salim Akil, and Caroline Dries. Set in a shared fictional multiverse much like the DC Universe and DC Multiverse in comic books, it was established by crossing over common plot elements, settings, cast and characters that span six live-action television series and two animated series.