Callen Martin
The Madeleine Milburn Literary Agency
Likely Open
Updated: 4/21/2026
Agent Info
Query Info
Genres
Agency Info
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.
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