In geometry, the tridiminished rhombicosidodecahedron is one of the Johnson solids (). It can be constructed as a rhombicosidodecahedron with three pentagonal cupolae removed.
thumb|3D model of a tridiminished rhombicosidodecahedron
Related Johnson solids are:
- : diminished rhombicosidodecahedron with one cupola removed,
- : parabidiminished rhombicosidodecahedron with two opposing cupolae removed,
- : metabidiminished rhombicosidodecahedron with two non-opposing cupolae removed, and
- : gyrate bidiminished rhombicosidodecahedron with two non-opposing cupolae removed and one cupola rotated 36 degrees.