Nightwing has a comic book history going all the way back to the Golden Age, even if he did spend over half of it in the role of Robin. Whether defending Bludhaven as Nightwing or fighting for Gotham City alongside Batman, Dick Grayson has always been one of DC's most prominent superheroes. Despite this notoriety, he's very rarely been a member of the Justice League.
Dick Grayson has been on the Justice League quite a few times, but rarely has it been in the role of Nightwing. These involved the '90s expansion of the League into several spin-off teams as well as a story in which many of the main heroes on the team were stranded in the past. Here's a look at how the former Boy Wonder finally grew up, temporarily leaving behind the Titans for the big leagues.
Justice League: Task Force
Nightwing first joined the League, or at least a version of it, in the pages of David Michelinie and Sal Velluto's Justice League: Task Force. This series, much like Extreme Justice, was emblematic of some of the darker, grittier comics of the 1990s, featuring moodier art and more grisly storylines involving international terrorism and other such plots. The team has United Nations backing, with their premise being to go out and embark on special strike missions.
Nightwing showed up early into the team's foundation, being sent to join in the place of Batman, to serve alongside of the team's unofficial leader Martian Manhunter. The former sidekick would have a rocky start on the team, with Martian Manhunter angrily informing him that the Justice League Task Force wasn't the Titans. His time on the team wouldn't last long though, as he soon found out why he was invited.
Justice League Task Force's first mission was to deal with a group of rebels who were attempting to overthrow their president. Nightwing soon had the politician in his crosshairs but is unable to pull the trigger and kill him. It's revealed that this is exactly why the team's U.N. correspondent wanted him as he knew he would never kill, which would cause him to fail. When he discovers this less than moral reasoning behind the team, Nightwing and Wally West both quit.
JLA: The Obsidian Age
Nightwing would join the more traditional Justice League some years later in Joe Kelly and Doug Mahnke's "The Obsidian Age" storyline, though his team was a replacement for the main one. This story came after the events of "Our Worlds at War," and featured mainstay Justice League heroes such as The Flash, Wonder Woman, Superman and others traveling back in time to recover the lost kingdom of Atlantis. This resulted in their disappearance as well, with Batman quickly forming a replacement League in their stead.
With the heroes gone for over a month, mounting crime forced a new JLA to be created. The members included the recently revived Oliver Queen, a.k.a. Green Arrow, as well as other stalwart heroes such as Zatanna, Firestorm, and the Atom. Leading them was none other than Nightwing, who Batman himself announced as the only logical choice for the position. Dick quickly showed himself to be a capable leader of other heroes both younger and older, firmly getting down to business in order to fix the world's growing problems.
After this storyline, however, he quit the team once the real League was firmly back in place. He clearly felt more at home being either his own man or fighting alongside the Titans, shown by how uncomfortable he seemed to be when he took on the role of Batman and served in the League again years later. He'd join the League again more recently in the storyline "Death Metal," but this too was a temporary membership. It seems like for Dick Grayson, the Justice League is the team that he always admires, but seldom wishes to actually serve on.