Computing the Euclidean spacetime action on-shell provides a useful way of both testing holographic proposals and determining the string theory sphere partition function. We consider families of three-dimensional linear dilaton spacetimes for which there are holographic proposals that share features of a T\overline{T}-deformed CFT. We extend the holographic renormalization program beyond AdS to this class of geometries by identifying the boundary terms needed for a well-defined variational principle and a finite on-shell action. We show that the spacetime energy or mass determined from the on-shell action matches the T\overline{T}-deformed two-dimensional CFT energy. This provides more evidence for the role of the T\overline{T} deformation in this holographic correspondence.
