Seiyū (声優, also written seiyuu or simply seiyu) is a Japanese term that roughly equates to a voice actor/actress for radio, television and video games. On television, they are mostly used in anime and commercial advertisements, and are somewhat more famous than voice actors traditionally are in America.
Conventional usage among American fans is: when speaking of a character in a series translated into English to use seiyū to refer to the Japanese actor and simply voice actor for the English one.
American fandom is sometimes divided over the opinion that some prominent seiyū will "perfect" certain voice types (e.g. the ditsy schoolgirl, the deep-voiced loner) sometimes resulting in these seiyū becoming typecast.
Notable seiyū and their major roles (Japanese version unless noted):
