Iszm is a planet in the Alpha Quadrant. The planet has very light gravity, allowing plant lifeforms to grow extremely large.

In 2372, Jadzia Dax obtained a bonsai tree originating from Iszm for Jonathan Vance that Miles O'Brien delivered to him. (DS9 novel: Trapped in Time)

The name of the planet appears to be a homage to the science fiction novella The Houses of Iszm, which featured the planet Iszm and giant trees in which the planet's inhabitants lived.