Wikipedia:How to rename (move) a page
If you discover that you've created a page with the wrong title (maybe you misspelled it, maybe you didn't follow the naming conventions and you want to make it fit in more cleanly with the rest of Wikipedia), you can rename it by moving it to a new title.
(Note that you have to be logged in to rename a page this way.)
When you've got your article up, click on the "Move page" link in the sidebar. You'll be asked for a new name for the article, and given the option to also move the article's talk page. (Unless you know what you're doing, it's safest to say yes.) Click the magic button, and the page will be renamed using the new title. The old title will become a redirect page, so any links to the old title will still go to the new page.
Notes
The nice thing about using the "move page" function is that it keeps the entire edit history of the article, before and after the move, in one place; it's as if the article were always named that way. So, it's preferable to use this method over just cutting text out of one article and cramming it into a new one; old revisions, notes, and attributions are harder to keep track of it you do that. (But you may have to if, for instance, you're splitting a page into multiple topics. If you do, please include a note in the new article's summary and talk page of where you took the text from.)
If the new title already exists, the wiki will tell you that you can't rename the article. You'll either have to manually merge the two pages together, or -- only if there's no content in the page -- ask to have it deleted to make room for moving the page.
Another thing to remember is that redirects to redirects aren't automatically followed (this prevents infinite loops and spaghetti linking). Always check the What links here for your page, and if there are multiple levels of redirects, go fix the links to point to the new location directly.
See also:
- How does one edit a page
- How to use redirect pages
- Practice editing pages in our Wikipedia sandbox!