There are a number of different settings in the Dungeons & Dragons multiverse for players to use, but there are some that can no longer appear due to licensing reasons. There are several popular D&D settings that players can use, but any DM can throw them out and create one of their own.
The current default setting for the fifth edition of D&D is the Forgotten Realms, but there books available for different settings, like the world of Eberron, where magic and technology work together. The Ravenloft campaign setting is returning in a few weeks, in Van Richten's Guide to Ravenloft, allowing players to visit numerous gothic horror-inspired realms. There are also several books that stat out planes from Magic: The Gathering, like Guildmasters' Guide to Ravnica and Mythic Odysseys of Theros.
There are still older D&D settings that have yet to return in the current edition of the game, like the spacefaring sci-fi Dungeons & Dragons setting Spelljammer. There are also some older campaign settings that are not allowed to return, nor can they be directly referenced in D&D media, due to rights issues and licenses that have changed hands over the years.
D&D Settings No Longer Official - Rokugan
Rokugan is the setting of a tabletop RPG called Legend of the Five Rings, which is a fantasy game with a world based on feudal Japan. The world of Rokugan was also used as an official D&D setting for the third edition version of Oriental Adventures. There was a time when the Legend of the Five Rings books had rules for both the main game and for D&D, but the publishers eventually scrapped the D&D content. Legend of the Five Rings and the Rokugan setting are now owned by Fantasy Flight Games, so it's unlikely that they will appear in future D&D materials.
D&D Settings No Longer Official - Kingdoms Of Kalamar
Kingdoms of Kalamar was created by Kenzer & Company as a campaign setting for the third edition of D&D, but it has since been repurposed for another tabletop RPG system. Kenzer & Company produce an RPG called HackMaster, which debuted as a parody of Advanced Dungeons & Dragons in a comic called Knights of the Dinner Table. The first edition of HackMaster used the Garweeze Wurld setting from Knights of the Dinner Table, in order to keep it close to the game played in the comics. Over time, Kenzer & Company released a new version of HackMaster that used the Kingdoms of Kalamar as its setting, so it's unlikely to be adapted for the current edition of D&D.
D&D Settings No Longer Official - Lankhmar
Lankhmar is the name of a city from the Fafhrd and the Gray Mouser novels, which themselves were an inspiration for D&D. Lankhmar received an official supplement for Advanced Dungeons & Dragons, allowing players to have adventures in the setting. The license has since changed hands a few times and it's currently owned by Goodman Games, with Lankmar now being used for an RPG called Dungeon Crawl Classics.
It's not unfeasible that the license for any of these properties could end up under Wizards of the Coast/Hasbro's control in the future, even if it's just a temporary arrangement, but these old Dungeons & Dragons settings are unlikely to return for the fifth edition of the game, and won't be directly referenced in the books outside of subtle mentions.
Source: Fantasy Flight Games, Kenzer & Company, Goodman Games