When will dear john be on HBO or starz?

"Dear John" is not a TV show, it's a movie. It was released in 2010 and is not currently available on HBO or Starz. You can, however, find it on streaming services like:

* Netflix (in some regions)

* Amazon Prime Video (for rent or purchase)

* YouTube (for rent or purchase)

* Google Play (for rent or purchase)

* Vudu (for rent or purchase)

It's always a good idea to check the specific streaming services in your region to see if they have it available.