How do I move an issue on github to another repo?

No, officialy you can't move issues between repositories.

There is a hack though, github-issues-import, kind of a plugin, to import issues from a repository to another.

I've created a Chrome Extension called Kamino that will clone issues from one repository to another. It will also close the original issue. It will also eventually be available for MS Edge.

https://chrome.google.com/webstore/detail/kamino/ffdebockfdjileaojbbccofhgncmioaf?hl=en-US

See the GitHub docs on transferring issues.

Transferring an open issue to another repository

On GitHub, navigate to the main page of the repository.

Under your repository name, click Issues.

In the list of issues, click the issue you'd like to transfer.

In the right sidebar, click Transfer this issue.

If you have the ZenHub integration you will see this button at the very lower-right when viewing an issue. This allows the issue to be copied to another repo in the same organization, or copied and closed.

And yes, "Move Issue" is a misnomer.

There seems to still be no way to move (copy and delete) or to just delete, a mistakenly-submitted issue.

EDIT: Beware, the v1 of this feature has major limitations like leaving behind some(most?) of the issue's metadata, not notifying subscribers, etc.