Clarissa is voiced by Avital Ash.
To any outsider, appears to have the world on a string. Extremely popular among the students (and well-liked among parents and teachers for her seeming ease at attaining good grades), she nonetheless has a darkened edge that comes with her coldness to strangers and general anxiety for the future. She used to date Alex's late brother, Michael, and she holds Alex responsible for his untimely death. Shannon Doherty in "Heathers" or Rachel Adams in "Mean Girls" (without that Valley Girl voice).
Clarissa is taller than all of the other character in-game, aside from Jonas and Michael. She has short red hair and reddish-brown eyes. She wears a blue v-neck shirt with jeans, a long gray jacket, and brown knee-high boots.
In memory sequences, Clarissa wears a blue button-up shirt, dark grey pants, and brown ankle boots.
Clarissa lives in Camena, Oregon, with her family. She is very popular at school and is said to have been the homecoming queen for several years running. She also grew up around Alex, who thought of herself as the "annoying little sister" that Clarissa always had to sneak around, and is neighbors with Ren.
Around the time of Nona's last birthday, a mutual friend of theirs was involved in a car accident, causing Nona to cancel her birthday plans so she could visit them in the hospital instead. Afterward, Clarissa still came to Nona's house with a huge birthday cake and stayed up to watch movies with her.
One year prior to the beginning of Oxenfree, Clarissa had been dating Alex's brother Michael for around three months. The three of them went to Edwards Island together so they could all hang out. As Clarissa and Michael got closer to graduation they considered moving to New York together. However these plans were dashed upon Michael's untimely death, drowning while swimming with Alex, an event she holds Alex responsible for.
After Michael's death, is it implied that Clarissa may have gone into therapy to help with her grief, though she claims it has not worked.
- Alex - Clarissa and Alex seem to have always had a somewhat antagonistic relationship while growing up. Once Clarissa began dating Michael she tried to reach out to Alex, understanding that Michael thought very highly of her and not wanting to make things weird for Alex. However after Michael's death their relationships became strained, with both having resentments towards each other fueled mainly by their grief. When playing a round of "Marry, Screw, Kill" during the game of Truth-or-Slap, Alex can say she'd marry Clarissa just to spite her (or because Alex is sarcastically delighted to be able to hear her "biting wit" every day, or just because Clarissa is tall and would be able to reach the top shelf), sleep with her because she is "obviously" attractive (to which Jonas responds by asking if Clarissa believes that, and Clarissa responds confidently with "No, I believe her. I mean, look at me."), or kill her if left with no other options (by which Clarissa is unsurprised).
- Michael - Clarissa and Michael dated prior to the events of Oxenfree, and the two are shown to have a healthy relationship, with both of them caring deeply about Alex's wellbeing. Depending on player choices, it is possible for Alex to convince Michael to stop dating Clarissa before he dies. It is unknown whether or not this ultimately affects Clarissa's behavior at the end of the game, as she still responds with the same amount of grief as to his death. She will always blame Alex no matter what.
- Nona - Nona is one of Clarissa's best friends who she claims to love "like a three-legged puppy." Nona is one of the few people who will see Clarissa further than just the popular hot chick at school, recognizing that deep down Clarissa is a good person because of their closeness and friendship. Sometimes, due to Nona's more submissive personality, Clarissa is slightly manipulative towards her and her actions, but Nona doesn't seem to mind and rather idolizes and mimics her.
- Jonas - Upon meeting Jonas, Clarissa is appalled at the idea that Jonas is Alex's new step-brother, somewhat implying the idea that Jonas is a replacement for Michael. The two do not interact much in-game besides her trying to convince him to keep his distance from Alex, so for the most part, the relationship is negative-neutral.
- Ren - Possibly due to Ren and Nona's friendship, Clarissa will state that she views Ren as a friend by association (though, will "downgrade [him] to a creepy neighbor" in the beginning of Oxenfree). The two do not interact much in-game, but Clarissa will purposely try to get Ren to admit his crush on Nona to embarrass him during Truth-or-Slap.
Depending on the choice made by the player, the game can end in multiple ways that affect Clarissa's relationship with Alex.
Made up with Clarissa
If Alex is kind towards Clarissa and chooses to spare her from the Sunken, they can make up by the end of the game. Clarissa goes on to study English literature at college and gets a dog. She still talks with Alex, though not often. She also gains a fear of the ocean.
Made Clarissa hate Alex
Clarissa moves to the east coast, drops out of college, and works at a boutique. She also gains a fear of the ocean.
Preserved relationship with Michael
During certain memory sequences in the game, Alex has the ability to convince Michael to stay in town, and thus prevent Michael from drowning later on, and can also influence his relationship status with Clarissa. Alex giving Michael her "blessing" will allow Clarissa and him to still be in a relationship while Clarissa goes to college. The two of them will make plans to elope to New York City (which Alex likens to a wedding from The Boxcar Children).
No longer with Michael
Convincing Michael to break up with Clarissa will cause them to no longer be together at the end of the game.
If Alex chooses to exit through the rift during the game's climax and sacrifice Clarissa, then she will be entirely erased from time. No one will remember her apart from Alex, who mentions that she thinks about her every day after the incident, and goes on to doubt if she did the right thing.
- Clarissa's worst fear is dying with too many regrets.
- She plans to get an ampersand tattoo on her ring finger once she moves out of her parents' home.
- According to Nona, she taps her nails when she's bored.
- She has a sister.
- She has a dog named Charlie, and gets another dog after one version of the ending.