Sidemore may refer to:
- Sidemore, an inhabitable planet in the Marsh System.
- the Republic of Sidemore, the planet's governmental authority.
- the Sidemore Navy, the Republic's armed space forces.
- the Sidemore Presidential Medal, a medal awarded to Honor Harrington.
- Sidemore Station, an RMN base in the Marsh System.
- Task Force Sidemore
- Aaron Sidemore, Grayson Minister of Justice around 1905 PD.