+1
Well, first of all, foreign from whose perspective? Are you asking about non-American actors? Or are you asking about non-British actors? Are you asking about non-English speaking actors? Or what?
The international distribution of film at its current level means that the term “foreign” really doesn't (and shouldn’t) apply to actors working at that level.
Are you asking about actors of certain nationalities who are less well known outside their own country? Then please phrase your question this way. As it stands, I find your question mildly offensive.
My actual list of international acting talent is too long to put down here. I’ve listed a few outstanding actors from numerous countries here, but this is a very limited list and is actually an insult to all the actors and actresses I haven’t named here. The number of outstanding Serbian and Turkish actors unknown outside of their own countries is enormous just on its own.
Marcello Mastroianni (Italy) - possibly the greatest film actor of all time
Anna Magnani (Italy)
Sophia Loren (Italy)
Virna Lisi (Italy)
Luigi lo Cassio (Italy)
Andrea Tidona (Italy)
Michele Riondino (Italy)
Yon Gonzalez (Spain) - of the younger generation, just wow
Concha Velasco (Spain)
Pep Anton Munoz (Spain)
Eloy Azarin (Spain)
Adriana Ozores (Spain)
Laura Morante (Italy)
Irene Papas (Greece)
Catherine Deneuve (France)
Isabel Huppert (France)
Charles Berling (France)
Gerard Depardieu (France)
Fanny Ardant (France)
Daniel Auteuil (France)
Isabel Adjani (France)
Fabrice Luchini (France)
Vincent Lindon (France)
Sandrine Kiberlain (France)
Romain Duris (France)
Mathieu Amalric (France)
Max von Sydow (Sweden)
Liv Ullmann (Sweden)
Bibi Anderson (Sweden)
Pernilla August (Sweden)
Sidse Babett Knudsen (Denmark)
Barbara Sukowa (Germany)
Hanna Schygulla (Germany)
Rade Šerbedžija (Serbia)
Rossy de Palma (Spain)
Carmen Maura (Spain)
Marisa Paredes (Spain)
Halit Ergenc (Turkey)
Berguzar Korel (Turkey)
Ahmet Rıfat Şungar (Turkey) - also of the younger generation, again, just wow
Ronit Elkabetz (Israel) - Elkabetz died of cancer in 2016 at the age of 52. She was probably the greatest actress Israel has ever produced - a phenomenon.
Hiam Abbas (Israel)
Mari Törőcsik (Hungary)
Gong Li (China)
Leslie Cheung (China)
Carlos Riquelme (Mexico)
Sonia Braga (Brazil)