Cassandra O’Leary Books in Order

  • 11 Books
  • 2016 – 2024 Published

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Reading order
5 of 5 reading orders shown

Where to Start with Cassandra O’Leary

If you are new to the witty, emotional, and sun-drenched romantic comedies of Australian author Cassandra O’Leary, the best starting point is her award-winning debut novel, Girl on a Plane. Originally published in 2016 by HarperCollins UK after winning the global We Heart New Talent contest, this flagship book was re-released in a revised second edition in 2023. It introduces the core characters and the signature style that O’Leary is known for: a blend of high-flying travel drama, sizzling chemistry, and distinct Melbourne charm.

However, if you prefer a chronological flow or love holiday-themed romance, you can also begin with the prequel novella, Girl Under the Christmas Tree, which introduces characters who play major roles later in the series.

The “Girl on a Plane” Series Reading Orders

The "Girl on a Plane" universe features a mix of full-length novels and companion novellas. Because some stories run concurrently or follow different couples, you can read them in either chronological order or by their publication dates.

Option 1: Chronological Reading Order (Recommended)

Reading the series chronologically allows you to watch the relationships develop in a natural timeline, especially for the supporting characters who eventually get their own happy-ever-afters.

  1. Girl Under the Christmas Tree (2020) – Book 0.5. A festive prequel novella set at a luxury Alpine hotel, introducing Yuki Yamimoto (a hotel guest relations manager) and Irish tech CEO Declan Moriarty.
  2. Girl on a Plane (2016 / 2023) – Book 1. The flagship novel. Follows flight attendant Sinead Kennealy and Australian corporate executive Gabriel Anderson as they clash and connect during a turbulent flight and a subsequent layover in Singapore.
  3. Girl on a Babymoon (2023) – Book 1.5. A sequel novella focusing on Sinead and Gabriel as they prepare for parenthood and face new relationship challenges.
  4. Girl on a Layover (2023) – Book 2. A second-chance romance novella that returns to Yuki and Declan (from Book 0.5) as they meet again at a destination wedding.
  5. Girl in the Snow (2024 / 2025) – Book 2.5. A cozy holiday novella about flight attendant Deanna Michaelson, who escapes to a remote New York lodge and gets snowed in with grumpy manager Cal Winterbourne. Originally featured in the 12 Tropes of Christmas anthology before its standalone release.
  6. Girl on an Island (2026) – Book 3. A friends-to-lovers, forced-proximity romance set in Australia's beautiful Whitsunday Islands, focusing on Bridie (Sinead's sister) and her brother's best friend.

Option 2: Publication Reading Order

If you prefer to read the books in the exact order the author wrote and released them, follow this path. Note that the prequel novella was released four years after the debut novel.

  1. Girl on a Plane (2016 / 2023) – Book 1
  2. Girl Under the Christmas Tree (2020) – Book 0.5
  3. Girl on a Babymoon (2023) – Book 1.5
  4. Girl on a Layover (2023) – Book 2
  5. Girl in the Snow (2024) – Book 2.5
  6. Girl on an Island (2026) – Book 3

Deep Dive: The Series Connections

While the "Girl on a Plane" books can technically be read as standalones, they are deeply interconnected through character friendships and family ties. Sinead Kennealy is the central link: she is the protagonist of the main novel and its babymoon sequel, Yuki's close friend, and Bridie's sister. Reading the stories out of order won't ruin the plots, but you will encounter spoilers regarding who ends up together, particularly concerning Yuki and Declan's relationship arc which spans from Book 0.5 to Book 2.

Standalone Novels and Short Story Collections

Beyond her main aviation-themed romance series, Cassandra O’Leary has published standalone contemporary romances and short story collections that showcase her versatility in the rom-com genre.

Dating Little Miss Perfect (2023)

A complete standalone contemporary romantic comedy. It follows a perfectionist heroine who must navigate the unpredictable world of modern dating, delivering O'Leary's classic blend of Australian humor, relatable character flaws, and heartfelt romance. There are no crossover characters from the "Girl on a Plane" series, making it an easy pick-up-and-read option at any time.

Hot in the City (2022 Collection)

For readers who enjoy quick, sweet, and steamy reads, this anthology collects four of O'Leary's popular short stories and novellas. These stories are set against vibrant backdrops like Melbourne and are perfect companion pieces for a quick reading session:

  • Chocolate Truffle Kiss (2016) – A charming novelette about a lonely writer and a talented barista, set in a cozy café.
  • Heart Note (2017) – A holiday rom-com novella about a department store worker, Lily, finding festive romance.
  • Tree Love (2018) – A lighthearted romantic short story.
  • Friday I'm In Love (2022) – A workplace "sweet and saucy" romance novelette focusing on Megan, who realizes the neighbor she has been watching from afar is the new auditor at her office.

What to Know Before You Start

Cassandra O'Leary's books are celebrated for their strong, independent heroines and authentic modern dilemmas. As an Australian author, she frequently infuses her work with local settings (like the suburbs of Melbourne or the tropical Whitsunday Islands) and Aussie terminology, alongside global travel destinations. If you enjoy authors like Sophie Kinsella, Christina Lauren, or Marian Keyes, you will find a similar balance of laugh-out-loud comedy, realistic relationship issues, and steamy chemistry in O'Leary's bibliography.

Frequently Asked

Do I need to read the Girl on a Plane series in order?

While each book has its own self-contained romantic arc, it is highly recommended to read them in order. Girl on a Layover spoils key elements of Girl Under the Christmas Tree, and Girl on a Babymoon directly continues the story of Girl on a Plane.

Where is Cassandra O'Leary from?

Cassandra O'Leary is an Australian author born in Dandenong, Victoria. She currently lives in Melbourne, which serves as the setting for many of her contemporary romances and short stories.

Are there any standalone books by Cassandra O'Leary?

Yes. Dating Little Miss Perfect (2023) is a complete standalone contemporary romantic comedy. Additionally, her short story collection Hot in the City features standalone novelettes.

Is Girl in the Snow part of the main series?

Yes. Girl in the Snow is Book 2.5 in the Girl on a Plane series. It is a festive, holiday-themed novella focusing on flight attendant Deanna Michaelson and lodge manager Cal Winterbourne.

What is the relationship between Girl Under the Christmas Tree and Girl on a Layover?

Both books follow the romance between Yuki Yamimoto and Declan Moriarty. Girl Under the Christmas Tree (Book 0.5) serves as their introduction, while Girl on a Layover (Book 2) details their second-chance romance.

When is Girl on an Island released?

Girl on an Island is Book 3 in the series and is scheduled for release in 2026. It features Bridie (Sinead's sister) in a friends-to-lovers story set in the Whitsunday Islands.