King dominated Dolan from the outset, much to the disappointment of a raucous crowd in Dublin.
The Englishman stormed into a 2-0 lead despite missing a series of doubles, scoring heavily throughout to deny Dolan a way back into the match.
Dolan briefly threatened a rousing comeback when he reduced the deficit to 3-1, but King proved too strong to prevail by five legs to two, finishing on a magnificent 132 checkout.
King will meet Michael van Gerwen in Sunday's final after the Dutch sensation stormed past Wes Newton with a brilliant semi-final display.
The 23-year-old thrashed Newton 5-1 to make his first major final in impressive fashion.