  We introduce a quasidilaton scalar field to the minimal theory of massive
gravity with the Minkowski fiducial metric, in such a way that the quasidilaton
global symmetry is maintained and that the theory admits a stable
self-accelerating de Sitter solution. We start with a precursor theory that
contains three propagating gravitational degrees of freedom without a
quasidilaton scalar and introduce St\"uckelberg fields to covariantize its
action. This makes it possible for us to formulate the quasidilaton global
symmetry that mixes the St\"uckelberg fields and the quasidilaton scalar field.
By the Hamiltonian analysis we confirm that the precursor theory with the
quasidilaton scalar contains four degrees of freedom, three from the precursor
massive gravity and one from the quasidilaton scalar. We further remove one
propagating degree of freedom to construct the minimal quasidilaton theory with
three propagating degrees of freedom, corresponding to two polarizations of
gravitational waves from the minimal theory of massive gravity and one scalar
from the quasidilaton field, by carefully introducing two additional
constraints to the system in the Hamiltonian language. Switching to the
Lagrangian language, we find self-accelerating de Sitter solutions in the
minimal quasidilaton theory and analyze their stability. It is found that the
self-accelerating de Sitter solution is stable in a wide range of parameters.
