Depends on how much smaller my planet was. If my Earth were too small to create enough gravity to hold an atmosphere or an ocean, I would not be here -- indeed, no life would be here -- to get upset over too small a planet.
I'm sure it's the same situation on your planet.
Planets orbit stars, not other planets. A planet-like object that orbits a planet is a moon.
No known planet is smaller than Mercury since Pluto was reclassified as a Dwarf Planet.
Eris is not a planet; it is a dwarf planet. It is much smaller than Earth.
Mercury
Mercury is smaller than Titan, but Titan is a moon, not a planet.
Mercury, Venus and Mars are all smaller than the Earth. If the question is referring to the US as in the US of A, then no planet is smaller.
Mars is the only planet which is both smaller and colder than the Earth.
No known planet is smaller than Mercury since Pluto was reclassified as a Dwarf Planet.
Eris is not a planet; it is a dwarf planet. It is much smaller than Earth.
Jupiter is not a star. It is a planet. However, there are stars that are smaller than the planet Jupiter.
Pluto is the dwarf planet that is smaller than the Earth's moon.
none, the moon is smaller than all the other planets in our solar system.