Marvel's Agents of S.H.I.E.L.D., or simply Agents of S.H.I.E.L.D., is an American television series created for ABC by Joss Whedon, Jed Whedon, and Maurissa Tancharoen, based on the Marvel Comics organization S.H.I.E.L.D. (Strategic Homeland Intervention, Enforcement, and Logistics Division), a fictional peacekeeping and spy agency in a world of superheroes. It is set in the Marvel Cinematic Universe (MCU), sharing continuity with the films and other television series of the franchise. The series is produced by ABC Studios, Marvel Television, and Mutant Enemy Productions, with Jed Whedon, Tancharoen, and Jeffrey Bell serving as showrunners.
The series revolves around the character of Phil Coulson, with Clark Gregg reprising his role from the film series, and his team of S.H.I.E.L.D. agents, who must deal with various unusual cases and enemies, including Hydra and the Inhumans. Joss Whedon began developing a S.H.I.E.L.D. pilot following the success of his film Marvel's The Avengers, and Gregg was confirmed to reprise his role in October 2012. The series was officially picked up by ABC in May 2013, and also stars Ming-Na Wen, Brett Dalton, Chloe Bennet, Iain De Caestecker and Elizabeth Henstridge, with Nick Blood, Adrianne Palicki, Henry Simmons, Luke Mitchell, and John Hannah joining in later seasons. Prosthetic makeup is created with Glenn Hetrick's Optic Nerve Studios, while Legacy Effects contributes other practical effects. The visual effects for the series are created by FuseFX, and have been nominated for multiple awards. Several episodes directly crossover with films or other television series set in the MCU, while other characters from MCU films and Marvel One-Shots also appear throughout the series.
The first season originally aired from September 24, 2013, to May 13, 2014, while the second season aired from September 23, 2014, to May 12, 2015. A third season premiered on September 29, 2015, concluding on May 17, 2016, and the fourth season premiered on September 20, 2016, and concluded on May 16, 2017. A fifth season of Agents of S.H.I.E.L.D. is scheduled to premiere in late 2017. After starting the first season with high ratings but mixed reviews, the ratings began to drop while reviews improved. This led to much lower but more consistent ratings, as well as more consistently positive reviews in the subsequent seasons.
Several characters created for the series have since been introduced to the comic universe and other media, while a spin-off series, centered on Blood and Palicki's characters Lance Hunter and Bobbi Morse and titled Marvel's Most Wanted, received a pilot order in August 2015; it was ultimately passed on in May 2016. An online digital series, Marvel's Agents of S.H.I.E.L.D.: Slingshot, centered on Elena "Yo-Yo" Rodriguez, was launched in December 2016 on ABC.com.