Callen Martin
The Madeleine Milburn Literary Agency
Likely Open
Updated: 4/21/2026
Should You Query This Agent?
1.
Agent Information
Agent Bio
Callen joined MMA in January 2026 from Bell Lomax Moreton where he worked previously, first as an assistant and then as maternity cover for a senior agent’s list, before building a Children’s, YA and New Adult list of his own.
Research Links
2.
Submission Requirements
Fiction Requirements
Nonfiction Requirements
3.
Genres
Genres Represented
Fiction
- Children's Fiction
- New Adult Fiction
- Young Adult - Fiction
Nonfiction
Genres Not Represented
None listed or not available
4.
About The Madeleine Milburn Literary Agency
Agency Profile
Described as ‘a major force in publishing’ (The Bookseller), MMA is a London-based literary agency representing authors across commercial and literary adult fiction, non-fiction and children’s.
Agency Links
5.
Other Agents At The Madeleine Milburn Literary Agency (6 Total)
Agent requirements, submission statuses, and other information can change without notice and are often subject to interpretation. The user should always review the agent's official website before submitting or determining whether to submit. This listing and determination of suitabilitty for querying are provided for informational purposes and does not constitute an endorsement. We're rooting for you—good luck!