William "Whilce" Portacio (/pɔːrˈtɑːʃi.oʊ/;[2] born July 8, 1963) is a Filipino American comic book writer and artist noted for his work on such titles as The Punisher, X-Factor, Uncanny X-Men, Iron Man, Wetworks and Spawn.

He grew up in places such as Midway Island and New Mexico before his family settled in San Diego, California.

He began reading comic books at the age of ten, when his neighbor decided to get rid of her husband's collection, and through this, he discovered the work of creators such as Jack Kirby and Neal Adams, who were the two most important influences on Portacio's art.

[8] Portacio attended his first comic book convention in San Diego, where Marvel Comics editor Carl Potts, upon seeing Portacio's portfolio, offered him the job inking over Frank Cirocco and Chris Warner's pencils on the 1984 series Alien Legion.

[9] Later he was given assignments as a penciller, and became noted for his work on such titles as The Punisher, X-Factor, and The Uncanny X-Men, for which he co-created the character Bishop with John Byrne.

Other notable series that Portacio worked on include Stone and Marvel's controversial Heroes Reborn storyline within Iron Man.