Jonathan Harris (November 6 1914–November 3 2002), born Jonathan Charasuchin, was a character actor best known for his TV work as Bradford Webster in The Third Man and Dr. Zachary Smith in Lost in Space.

Born in Bronx, New York to impoverished Russian Jewish emigres, Harris worked in a pharmacy, and received a pharmacology degree from Fordham University. In hopes of becoming an actor, he trained himself against his Bronx accent, and changed his name to make it easier to pronounce. In 1938, he married Gertrude Bergman, to whom he was married for 64 years. He went on to perform over 100 plays with stock companies nationwide, and first appeared on Broadway with Heart of a City in 1942, and toured with the USO in the Pacific Theater of Operations.

He first worked on live television in 1948, and made his film debut with Alan Ladd and James Mason in Botany Bay in 1953. Harris went back to television, appearing in The Third Man as Harry Lime's manservant. In 1965, he first appeared in the role of Dr. Zachary Smith in Lost in Space, where, originally cast as a one-shot character, he easily stole the show from his castmates. Many of his one-liners from the Bill Dana Show were reused in Lost in Space. Although he's considered something of a cult icon for this role, Harris became greatly typecast as a likeable villian.

Harris spent most of the remainder of his career as a voice actor, appearing in television commercials as well as cartoons such as The Banana Splits, My Favorite Martians , Battlestar Galactica, Rainbow Brite, Darkwing Duck, Happily Ever After, Problem Child, Freakazoid!, A Bug's Life, Buzz Lightyear of Star Command, and Toy Story 2. He also had several cameo and guest appearances, including Zorro, Bewitched, Ark II , Uncle Croc's Block , and Space Academy .

Harris reprised his role as Dr. Smith in the one-hour TV special Lost in Space Forever in 1998. However, unlike his costars in the original show (June Lockhart, Mark Goddard , Marta Kristen and Angela Cartwright) he refused a cameo in the motion picture version of Lost in Space later that year. He announced that if he was unable to play his own role in the movie, he wanted no part in it at all. Instead, Gary Oldman played the part of Dr. Smith.

Harris died on November 3, 2002 in Encino, California of a blood clot to the heart, just days before his 88th birthday.