|Full Name||Alexis Harper Castle|
| Significant |
| Pi (ex-boyfriend)|
Ashley Linden (ex-boyfriend)
|Parents|| Richard Castle (father)|
Kate Beckett (step-mother)
|Other family|| Martha Rodgers (grandmother) |
Jackson Hunt (grandfather)
Lily Castle (half sister)
Reese & Jake Castle (half twin brothers) 
|Appearances||Alexis Castle - List of Appearances|
|Portrayed by||Molly C. Quinn|
After her parents' divorce when she was four, Alexis was raised by her father, Richard Castle, although this seems to have been what Alexis herself wanted also. Her mother, Meredith, often visited from L.A.. At some point, they were joined by Rick's mother, Martha, who moved in with them after being swindled by her ex-husband.
When Alexis was five, Castle began teaching her how to play laser tag. They have since had the tradition of occasionally playing laser tag until one of them scores 1000 points to win.
Alexis attended high school at the fictional Marlowe Prep. An over-achiever, she barely seemed to have time for a party-girl social life, but has just enough of her father's genes to get into trouble every once in a while.
Alexis cycles through an ever-changing list of resume-building school activities: playing the violin, fencing, serving in a class advocate role in student government, cheerleading, serving as an assistant manager of the school play, and working several internships, particularly under Lanie in the second half of her senior year. Alexis also served a three-day internship at the precinct.
Alexis has been in two summer programs (including one co-ed program at Princeton), had taken several AP classes to get sufficient credits to graduate high school a semester early, and almost (but decided not to) studied abroad in Paris. She was valedictorian of her graduating class; her valedictory speech framed the closing scenes of the season 4 finale "Always".
As of 2012, Alexis is 18 years old and attending college at Columbia University.
Being a big fan of the band Blue Pill, she is the one who breaks the news of the death of the lead vocalist, Hayley Blue, to her father. Distressed over the rumors, she asks her father to confirm the news for her and later shows up at the precinct to ask about it. She later helps the team while investigate the case by telling them everything she knows about the band and later unknowingly helps Richard solve the case while listening to Hayley's last song. ("Famous Last Words")
Alexis has always had an interest in Castle's police work. She volunteered in the 12th Precinct for a community service project for school, where she labored in the evidence room to catalog and dispose of the mountain of unclaimed seized properties. At one point, she solved a "case" in the form of finding the owner of a family photo album which had been forgotten in the pile of unclaimed possessions. ("One Man's Treasure") Another one of her school projects involved conducting "blood spatter" studies through hammered tomatoes. ("Hell Hath No Fury")
Most recently, she spent the latter half of her senior year as an intern with the Medical Examiner's office, working for Lanie.
Alexis wrestled with the question of which college to attend. At first, she wanted to go to Stanford to study economics with her boyfriend Ashley. Later, after being advised otherwise by her father, she realized that she did need to be her own person.
Although she has not stated what she intends to study, she seemed to have a very clear idea of which classes she wants to take. She was also hurt by the fact that she did not get into Stanford early. Eventually, although Oxford and Stanford both accepted her and had ideal programs for her intended major, she decided to go to Ivy League school Columbia, which is in New York City. While she wants her personal space and independence, she also wants to stay close to her father and grandmother.
Alexis is more mature and responsible than her parents--(She mothers Castle, just the way Castle acts like a parent to Martha, his mother) a source of both admiration and consternation for her father. When we first meet her, she is turning down an alcoholic drink because she is underage - and the offer comes from her father. She is very bright, enjoys school, and is dedicated to following the rules and doing what's right.
While Castle often counsels her to enjoy her childhood and misbehave from time to time (as he had), he also struggles with his overprotective side. She often plays with her father, including activities such as fencing (sometimes with lightsabers) and laser tag. Through Alexis, Castle can indulge his immature side; however, as Alexis grows out of these games, he increasingly faces both the loss of her and the loss of his own youth.
Similarly, Alexis wrestles with the fact that, on one hand, she is mature beyond her years, but on the other, she is still a teenaged girl.
Alexis's social and interpersonal issues often parallel some aspect of the case Castle and Beckett are investigating; this synergy is usually noticed by Castle himself, though sometimes he will ask Alexis for advice on a tough case.
Alexis has changed slightly throughout the run of the series. Seemingly the perfect daughter, her arguments and disagreements with her father has increased over the years, although they eventually resolve their issues by the end of the day. Her impulsive teenaged nature tends to get the better of her at times, much to her father's worry.
|“||They're all I've got! Do you hear me? They're all I've got!||”|
–Alexis to Beckett, Cops & Robbers (4x07)
- Richard Castle - Alexis acts more like the parent to her sometimes childish "cool" father, Rick, although she still does go to him for advice. Richard has no idea how Alexis grew up to be so good, given his, Meredith's and Martha's history as stubborn people. Richard tries to let Alexis have fun and get in trouble like a normal teenager, although whenever she does show a hint of wildness or any act that is a strange attribute to her, he gets over-protective. Alexis is also protective of her father; for example when Josh Davidson was blaming Richard for Beckett's shooting, Alexis angrily leapt to her father's defense.
- Martha Rodgers - Alexis is very protective of Martha, who she calls "Grams", and Rick. Unlike her father, she was very upset at the thought of Martha moving out to live with Chet Palaburn.
- Meredith - Alexis's relationship with her mother is more mixed. While Meredith often visits to see her daughter, Alexis is often frustrated and bewildered by her mother's recklessness and irresponsibility. When Alexis was nine years old, Meredith once pulled her out of school and took her to lunch in Paris. When Alexis was a teenager, Meredith pressured her into lying to her principal they could go shopping. (Always Buy Retail) While Alexis loves her mother, she prefers to do so infrequently and from afar.
Although otherwise more mature than her father, Alexis has shown to get very caught up in her relationships and make poor decisions; not only did she move in with Pi far too quickly, but when applying early for Stanford to be with Ashley, she applied for courses based on what Ashley was taking rather than thinking about her own academic interests and strengths.
- Owen was her first serious boyfriend; Alexis arranged to start dating him at a "study group" (which consisted of just the two of them). Eventually, they ended up going to the prom together (he was her age, but had skipped a grade). Afterwards, things between the two of them deteriorated and eventually, Alexis dumped him.
- Alexis has had several boyfriends during the series. She met her second boyfriend (unnamed), at a Princeton summer program. After the program ended, he took a trip in Europe, but upon his return, procrastinated about calling her, nearly causing Alexis to break up with him altogether. It's unknown how long this relationship lasted or how it ended.
- Ashley Linden and Alexis began dating in their junior year of high school. Castle met Ashley when he charged into the apartment wielding a dueling pistol-- only to realize that he'd just interrupted a make-out session between Ashley and his daughter. Castle took an immediate liking to Ashley for his terrified reaction, calling him "respectful". Ashley's economics professor parents were fascinated by Castle, although they considered themselves above reading popular fiction. After Ashley was accepted to Stanford but instead though about going to a college in New York, so he and Alexis could still be together, she broke up with him, not wanting to get in the way of his dreams. When Ashley finally decided to go to Stanford after all, they got back together and Alexis decided to go to Stanford with Ashley, and even apparently move in with him if she got accepted so they could take the same classes together (although she soon reconsidered her potential academic choices). When Alexis wasn't accepted for early admission, she decided to give their long distance relationship a shot. However, Alexis had continual trouble getting in touch with Ashley. When her father and grandmother were held hostage during a bank robbery, Alexis reached out to Ashley for support, but he didn't have time to talk to her. This was the last straw, and she dumped him that night over the phone.
- Alexis started dating a poet named Max in Secret Santa, thought it's unknown how long they dated since then.
- While in Costa Rica, Alexis met a free-spirited guy name Pi, whom she brought back home to New York with her. The pair later moved into their own apartment together, much to Richard's dismay. Alexis and her father often argued of his disapproval of Pi and the latter's job monitoring honeybees in New York. Some time later, Alexis broke up with Pi when she realized that she didn't have anything in common with him anymore.
- Kate Beckett - Although approving and supportive of her father's pursuing, and later relationship with, Detective Beckett, she is still her father's daughter, hence often more worried about Rick's safety and the well-being every time her father's life is put on the line. Despite this, she holds Beckett in high regard and often even goes to her for advice, just as Castle goes to Beckett for advice on her sometimes, seeing as she was once also a teenaged daughter. Their relationship was somewhat strained after Kate and Rick officially began dating, but they have apparently regained their old friendly dynamic. When Beckett went missing shortly after her promotion to Captain, Alexis insisted to her father that she have an active role in the investigation, as she now thinks of Kate as family.
- Lanie Parish - Alexis worked with Lanie as an intern during the latter half of her senior year. She got along with Lanie and seems to remain close as Beckett suggest that Alexis would tell Lanie about her relationship.
- Paige - Alexis and Paige were friends in Hedge Fund Homeboys from school. In Vampire Weekend, they got invited to a senior supervised party the day before Halloween, Paige gets drunk and Alexis calls her dad to get them out, but when he insists to call her parents, Paige told him not to because her parents will murder her and to let her sleepover and Alexis pleaded to not call them because she'll get in trouble, but Castle warned her and to get him their number.
- Rina - Alexis was babysat by Rina- then known as Katrina- when she was 13, due to how overprotective Castle is. After Castle ran into Rina during a case, during which he learned that Rina had become a model, he arranged for her and Alexis to catch up with a High School Musical marathon, wanting to give Rina a friend outside the cutthroat world of modeling.
- Hayley Shipton
- As a little girl, Alexis's favorite stuffed animal was named "Monkey Bunkey", which she still has. (Little Girl Lost)
- Her favorite movies are the High School Musical series. (Inventing the Girl)
- She likes Hayley Blue (Famous Last Words) and Taylor Swift's music. (Anatomy of a Murder)
- Alexis's first word was denouement, according to her doting father. (Punked)
- When she was four, Alexis and her father went Christmas shopping in some mall in White Plains, New York, where she disappeared for about an hour and was later found behind a rack of winter coats, taking a nap. (Murder Most Fowl)
- Alexis' cell phone number is 212-555-0135. (Law and Murder)
- Alexis has never gotten into a fight, with the exception of her friend Lauren in Slice of Death.
- Her Blood type is A+. (Target)
- Castle would have named her "Cosmo" if she was a boy. (The Good, The Bad & The Baby)
- At age 7, Alexis had an imaginary friend for whom her father made an extra lunch for six months. (Death Wish)
|Cast||Nathan Fillion • Stana Katic • Jon Huertas • Seamus Dever • Tamala Jones • Ruben Santiago-Hudson • Molly C. Quinn • Susan Sullivan • Penny Johnson Jerald|
|Characters||Richard Castle • Kate Beckett • Javier Esposito • Kevin Ryan • Lanie Parish • Roy Montgomery • Alexis Castle • Martha Rodgers • Victoria Gates|
|Seasons||1 • 2 • 3 • 4 • 5 • 6 • 7 • 8|