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- Dr. Hartley M. Baldwin (aka "Kettle Belly," "Mr. Two-Canes") – Gulf, Friday, The Cat Who Walks Through Walls
- Col. Richard Baslim aka "Baslim the Cripple" – Citizen of the Galaxy
- Thorby Baslim aka Thor B. Rudbek "Rudbek of Rudbek" – Citizen of the Galaxy
- Betty – The Star Beast
- Gillian Boardman (Jill) – Stranger in a Strange Land
- Joseph Bonforte – Double Star
- Eunice Branca – I Will Fear No Evil
- Jacob Burroughs – The Number of the Beast, The Cat Who Walks Through Walls
- Hilda Burroughs (nee Hilda Corners) – The Number of the Beast, The Cat Who Walks Through Walls, To Sail Beyond the Sunset
Read more about this topic: List Of Robert A. Heinlein Characters