Kristin Ostby is a Brooklyn-based agent at Salky Literary Management with deep editorial roots at Penguin Random House and Simon & Schuster, specializing in middle grade, YA, and upmarket adult fiction with a strong appetite for mystery, humor, and rich ensemble casts.
In brief
Her editorial background—working with Stuart Gibbs, Tomie dePaola, and Alex Morgan before moving to agenting—signals she brings hands-on developmental instincts that few agents can match in children's and YA spaces.
Mystery and humor are the throughlines across every age category she pursues; if your book isn't at least a little funny or plot-driven, you may be swimming against her taste.
She explicitly welcomes picture book author-illustrators but does NOT accept picture book manuscripts from writers-only—a crucial gate that many queriers miss.
Her former editorial work at two of the largest children's imprints gives her direct relationships with the publishers most likely to buy the kinds of books she now represents.
Her submission form was observed closed as of May 2026—verify live status before querying, as this can change without notice.
Lately
I would ***love*** to see supernatural YA thrillers and mysteries like these! #MSWL
My kingdom for this readalike! #MSWL
Please send me your upmarket, cozy adult mysteries! #MSWL
Expressed strong enthusiasm for supernatural YA thrillers and mysteries, signaling this is a live, active priority—not just a standing wishlist item.
What Kristin is looking for
This is her most emphatic wishlist priority. She wants mystery and thriller across the full spectrum—contemporary whodunits, cozy mysteries, historical mysteries, paranormal and supernatural mysteries, and outright thrillers. A February 2026 post singled out supernatural YA thrillers and mysteries as something she is actively hungry for right now. Humor layered into mystery is a particular plus.
She's looking for adult fiction that sits at the intersection of literary sensibility and commercial readability—specifically in comedy, mystery, romance, and historical fiction. The work should feel smart and well-crafted without being inaccessible. Rich ensemble casts, distinct settings, and layered family dynamics elevate a submission. Word count over 95,000 is a likely dealbreaker across all her fiction categories.
She loves hooky, warm, and escapist stories aimed at younger YA and MG readers—think classic coming-of-age energy with a sprinkling of fantasy rather than full-on speculative world-building. Fish-out-of-water setups, strong friendships, and breezy pacing are hallmarks of what she wants here. Stories set outside of school—road trips, summer vacations, workplaces—are especially welcome.
Within YA, she's drawn to romance that includes a speculative element or plays with unconventional structure or timeline. She also wants frank, funny contemporary stories about romance and friendship in the vein of the TV show Insecure translated to a teen lens, and historical romance told from a BIPOC perspective. Pure contemporary romance without a twist or fresh angle is less likely to excite her.
Warm, character-driven MG friendship stories in the tradition of authors like Lisa Greenwald, Sarah Weeks, and Wendy Mass. She's also open to funny MG coming-of-age graphic novels from author-illustrators specifically—not scripts from writers alone.
She actively seeks to add picture book creator-illustrators to her list—people who both write and illustrate their own work. She is NOT accepting picture book manuscripts from writers who do not also illustrate. This is a firm gate, not a soft preference.
Not the right fit
On Kristin's list
Taste fingerprint
How to query Kristin
Her form was closed as of late May 2026—check her agency page at Salky Literary Management for the current status before doing anything else.
Lead with genre and age category in the first line of your query; she represents a wide range across MG, YA, and adult, so clarity upfront matters.
If you're querying a mystery or supernatural thriller, name that explicitly and early—this is her loudest stated priority right now.
Word count is a real filter: if your manuscript exceeds 95,000 words, she has said it is probably not for her. Do not try to round down.
Humor, ensemble casts, and family-subplot texture are recurring signals in her taste profile—if your book has any of these, call them out concisely in the pitch.
Picture book queries from writers-only will not be considered; only submit if you are also the illustrator of your work.
Her editorial background means she responds well to craft and voice—a clean, well-written query letter is not optional.
If your story is set somewhere unusual—a road trip, a summer job, a vacation destination—mention the setting prominently, as she has explicitly flagged non-school settings as appealing in YA.