An exemplary method includes an unintended-dialing detection and prevention system 1) determining, based on an unintended-dialing detection heuristic, a phone dialing pattern associated with a phone dialing event of a phone device, 2) determining, based on the unintended-dialing detection heuristic, that the phone dialing pattern associated with the phone dialing event matches a predefined phone dialing pattern indicative of unintended dialing, and 3) automatically performing, in response to the determining that the phone dialing pattern associated with the phone dialing event matches the predefined phone dialing pattern indicative of the unintended dialing, an operation configured to prevent a placement of a phone call by the phone device in response to the phone dialing event. Corresponding methods and systems are also disclosed.