You can use Wowhead's Quest Completion Tool to view information about your character's quest completion through all zones currently in the game.
Enter your realm and character name to load your character in the tool.
After your character loads, you can select a region and zone. This will display all the quests that you have not completed in the zone, as well as show a map for the starting points of the quests. Clicking on the quest names will take you to the individual quest page.
The Quest Completion uses data from the World of Warcraft Armory. Your character's information may not be accurate if your Armory hasn't been updated.