Kevin Reilly announced Thursday he'll be leaving Fox by the end of June, according to a Fox statement.
Reilly was responsible for shepherding numerous hit shows at Fox, including "New Girl," "Glee," "The Following," "Sleepy Hollow" and "Brooklyn Nine-Nine." He also worked on "The Shield" and "Nip/Tuck" at FX.
"Peter [Rice, Fox Networks chairman and CEO] and I have been discussing this transition for a while," Reilly said in the statement. "It felt like the timing was as right as it could be."
It follows a rough year for the network, according to the Associated Press, with "American Idol" suffering a severe decline. This follows several strong years that "Idol" had led, but its 2014 season finale was down 66 percent from three years ago.
Reilly followed the announcement with a Q&A with the Hollywood Reporter. He said he's looking at working in either cable or online programming. He'd also changed the way the network was approaching pilot season, and it's unclear if his successor will maintain the same approach.
He also said that he hadn't had a chance to speak to some of the producers of new shows yet, and still had to talk to them about what his exit means for their projects.
"I haven't had a chance. I'm going to start doing that whole thing now," Reilly told the Hollywood Reporter.
Reilly started with Fox in 2007 and served as entertainment chairman since 2012. He'd previously worked as entertainment president at NBC, working on shows including "The Office," "Heroes" and "30 Rock," as well as previously shepherding "The Sopranos."
Reilly thanked Fox and other members of the leadership in the statement. Rice, who Reilly cited as being part of his exit, praised Reilly in the statement.
"Kevin and I have been discussing his desire for a new challenge for some time, so while everyone at the network will miss his enthusiasm for adventurous television, we all respect his decision and agreed that after the upfront presentation was the right time," Rice said.
Reilly is set to be inducted into the Broadcasting & Cable Hall of Fame in October.
The senior executives who reported to Reilly are now set to report to Rice until a replacement is named.