There are multiple ways to contest deletion depending on the process being used. You may be looking for:
- Wikipedia:Requests for undeletion, for contesting uncontroversial deletions done through the simple proposed deletion or some speedy deletion processes
- Wikipedia:Deletion review, for contesting controversial or previously discussed decisions made at the main deletion venues
- Wikipedia:Proposed deletion § Objecting, for contesting an open proposed deletion
- Wikipedia:Articles for deletion § How to contribute, for contesting an open nomination at Articles for deletion
To contest another process, you may be looking for: