Directories to submit your podcast to

iTunes is bar far the most popular podcast directory, but that doesn't mean you should only submit your feed to Apple.
Below is a curated list of the top podcast directories to submit your podcast to. Note that iTunes, Google Play, and Stitcher require accounts in order to login and submit your podcast feed for approval. TuneIn has a public portal page that anyone can submit a podcast to.

Make sure that your feed validates before submitting, lest risk being rejected.
Tip: Ensure your feed has at least one episode live, otherwise your submissions will be rejected.