Forbes.com reports that Dwayne "The Rock" Johnson is the top grossing actor of 2013. Between Fast & Furious 6, G.I. Joe: Retaliation, Pain & Gain and Snitch, Johnson's movies grossed $1.3 billion worldwide this year. Robert Downey Jr. came in second with the success of Iron Man 3.
The success of Fast & Furious 6 helped place Vin Diesel at #4, and the late Paul Walker at #6.
Note that the article is only taking into account box office grosses, not earnings. Robert Downey Jr. was the actually the highest paid actor of 2013 with $75 million, as opposed to $46 million for Johnson.