Who was the first American actor in a Godzilla movie?

The first American actor to appear in a Godzilla movie was Raymond Burr in the 1956 American release of "Godzilla, King of the Monsters".

While the original Japanese film *Gojira* (1954) didn't feature any American actors, the Americanized version, *Godzilla, King of the Monsters*, included a significant amount of newly filmed footage featuring Burr as a news reporter who investigates the monster's attacks.