  Derrick's theorem is an important result that decides the existence of
soliton configurations in field theories in different dimensions. It is proved
using the extremization of finite energy of configurations under the scaling
transformation. According to this theorem, the $2+1$ dimension is the critical
dimension for the existence of solitons in scalar field theories without the
gauge fields. In the present article, Derrick's theorem is extended in a
generic curved spacetime in a covariant manner. Moreover, the existence of
solitons in conformally flat spacetimes and spherically symmetric spacetimes is
also shown using the approach presented in this article. Further, the approach
shown in the present article in order to derive the soliton configurations is
not restricted to a particular form of the field potential or curved spacetime.
