Chloe Sullivan (born 1987) is a fictional character from the television series Smallville, played by Allison Mack. She is a new character, introduced by Smallville creators into the Superman story; there is no mention of Chloe Sullivan in the Superman comics or in the movies.

She was born in Metropolis and she moved to Smallville with her family when her father started to work for LuthorCorp. When she was young, her mother left for reasons not revealed.

She is reporter and editor at The Torch, the newspaper at Smallville High School, where she attends the same class as Clark. She maintained a "Wall of Weird," on which she posted articles concerning the often bizarre and eerie events that take place in Smallville, many of which are related to the mutagenic effects of kryptonite from the meteor shower.

One summer, she interned at the Daily Planet.

She fancies Clark, which sometimes causes her to quarrel with Lana Lang. Fans of the show are divided as to whether they like Chloe or Lana better and as to which girl they would like to see win Clark's heart.

When Lana's parents died in the meteor shower that struck Smallville when Lana was but a toddler, she was adopted by her aunt. During Lana's teen years, her aunt married and moved to Metropolis, allowing Lana to move in with Chloe. They became like sisters, although they still had occasional fallings out over Clark and other matters.

In episode #3-11, "Delete" (first aired January 28, 2004), she identified Lois Lane as her cousin, who is "not interested in journalism."

In Season 3's finale, "Covenant", Chloe entered a building at the end, which then exploded, causing many to believe her dead. At the start of season 4, in "Crusade", Clark and her cousin Lois began investigating her apparent murder. In the episode "Gone", she was revealed to be alive. Lex Luthor told Clark how he faked her and her father's deaths to prevent Lionel from finding them. Lionel's people found her, and he sent someone to kill her. Her testimony helped convict Lionel of the murder of his parents.

In episode #4-10, "Scare", it is revealed that she found her mother in a mental hospital with a hereditary mental disease.