A felony conviction is like the gift that keeps on giving. Even after you've served your time, if you have a felony conviction you may find it difficult to get a job, and in some states you also lose your right to vote. But what about the right to renew your passport?
Whether or not your felony conviction will prevent you from renewing your passport depends on what your conviction was for and whether or not you've finished serving your sentence. For example, if you are on probation or parole, you may not be allowed to travel without prior approval. If your conviction was for international drug trafficking, if you are still under legal supervision the State Department may refuse to renew your passport.
If you are denied a passport and you really need to leave the country, you do have the option of applying for a passport renewal under a humanitarian exception. However, there's no guarantee that doing this will get you your passport.
The good news is that once you've finished serving your sentence, in most cases you will be able to get a new passport when your old one expires. However, just because you have a US passport doesn't mean that you can travel wherever you please. Other countries can and will deny entry to people with criminal convictions-even countries like Canada that don't require visas for US citizens. To make sure you don't run into any problems, you should research the entry requirements for each country you plan to visit.
Also, make sure to renew your passport well in advance of your trip. It takes at least 6 weeks for a passport to be issued if you request standard processing, and if you request expedited processing it will still take around 3 weeks. Applying earlier means you'll be able to spot and correct problems in the application process before your trip.