Of the 11 Academy Awards that were won by the "Lord of the Rings" film "The Return of the King", how many were won by the actors of the film?

"The Lord of the Rings" film series from director Peter Jackson won 17 Academy Awards from 30 nominations in total.

"The Lord of the Rings: The Return of the King" won 11 Academy Awards, including Best Picture, Best Director and Best Adapted Screenplay. None of the Oscars were won by actors.

https://en.wikipedia.org/wiki/The_Lord_of_the_Rings:_The_Return_of_the_King

The final movie "Lord of the Rings: The Return of the King" won 11 Oscars out of 11 nominations. Alas, none of these were for acting.
The Saturn Awards (handed out by the Academy of Science-Fiction, Fantasy and Horror Films) did include several actors. Elijah Wood (Frodo) and Sean Astin (Sam) won, while Viggo Mortensen (Aragorn), Ian McKellen (Gandalf), Andy Serkis (Gollum) and Miranda Otto (Eowyn) were nominated.

Source: https://www.imdb.com/title/tt0167260/awards/?ref_=tt_awd