Johanna V. Castillo is a senior agent at Writers House with a decorated editorial pedigree — including decades shaping major bestsellers — who now champions commercially vibrant, emotionally resonant fiction, with a particular passion for romantic comedies, upmarket women's fiction, and stories centering BIPOC voices.
In brief
Her editorial background is exceptional: she personally edited most of Colleen Hoover's titles at Simon & Schuster and has shepherded 44 New York Times bestsellers — a commercial track record that few agents can match.
Her current client roster reads like a who's who of literary Latino/a voices — Isabel Allende, Reyna Grande, Armando Lucas Correa, Agustina Bazterrica — signaling a deep, sustained commitment to Spanish-language and Latinx literature in translation and in English.
Despite stating her nonfiction list is 'highly selective,' her reputation was built on memoirs and nonfiction; if you have an exceptional nonfiction project, it is worth researching her recent deals before assuming the door is fully closed.
She named a romantic comedy with substance as a top wish-list item, and her love of bickering lovers, enemies-to-lovers, and high-stakes romance is consistent across multiple public statements — this is a genuine priority, not a passing interest.
As of October 2025 she announced she is closed to queries until 2026; verify her current status directly before submitting.
Lately
She publicly announced in mid-October 2025 that her query inbox is closed and will not reopen until 2026.
What Johanna is looking for
This is her single most explicitly stated priority. She wants rom-coms with real substance — wit paired with emotional weight. Her stated touchstone is a romantic comedy in the vein of the workplace-satire novel Partner Track: sharp, character-driven, commercially minded but not fluffy. Bickering lovers and enemies-to-lovers dynamics are among her favorite tropes.
She is drawn to women's fiction and book club novels that balance literary craft with wide commercial appeal. Stories with unconventional family dynamics, generational narratives, and unreliable narrators excite her. If it's pure romance without comedy, she wants the emotional stakes dialed all the way up — doomed lovers, wrenching circumstances, high consequence.
She is hunting for historical fiction so precisely rendered and freshly conceived that it feels almost contemporary. She is especially interested in new angles on WWII love stories, and in historicals that surface hidden female figures or unlikely heroes. A twist on the familiar — not a straightforward retelling — is what catches her eye.
Across both age categories, compelling BIPOC protagonists are her explicit criterion. She gravitates toward diverse retellings of classics and stories with complex, non-traditional family structures. Sub-genres she actively lists include LGBTQ fiction, family saga, and romance at the YA level.
She is open to these genres but only when they carry strong commercial appeal or a distinct literary sensibility. Her editorial history with a time-travel genre novel and a psychological thriller informs this taste — she responds to genre fiction that has something more to say. Hard sci-fi, epic fantasy, and high fantasy are explicitly off the table.
Though her reputation was built on nonfiction and memoir, she describes this area of her list as highly selective at present. She is not actively seeking new nonfiction clients; only exceptional projects with a compelling hook should be considered, and writers should check her most current guidelines before querying in this category.
Not the right fit
On Johanna's list
Taste fingerprint
How to query Johanna
She is currently closed to queries until 2026 — do not submit until you have confirmed she has reopened; submitting during a closed window typically results in no response or an automatic decline.
Paste your query letter and the first five pages (or up to one full chapter) directly into the body of your email — no attachments under any circumstances.
Lead your query with the emotional core and the stakes: she responds to stories that 'mean something,' so open with what is at risk for your character, not just the plot mechanics.
If querying a romantic comedy, make the wit evident in the query letter itself — she is looking for voice and substance together, not just a clever premise summary.
For historical fiction, name what is new or unexpected about your angle up front; she is not looking for conventional period drama but for a twist that reframes the familiar.
If your protagonist is BIPOC, say so early in the query — it is an explicit priority across YA, MG, and upmarket adult fiction.
Her nonfiction list is highly selective; if querying nonfiction, your hook must be unusually strong and you should check her most current guidelines to confirm she is considering it at all.
Avoid pitching anything that touches kidnapping as a plot driver, or that leads with horror, gore, or hard sci-fi elements — these are firm exclusions regardless of how the rest of the manuscript fits her taste.