Cell circuits having a diffusion break with avoided or reduced adjacent semiconductor channel strain relaxation and related methods are disclosed. In one aspect, a cell circuit includes a substrate of semiconductor material and a semiconductor channel structure(s) of a second semiconductor material disposed on the substrate. The semiconductor material applies a stress to the formed semiconductor channel structure(s) to induce a strain in the semiconductor channel structure(s) for increasing carrier mobility. A diffusion break comprising a dielectric material extends through a surrounding structure of an interlayer dielectric, and the semiconductor channel structure(s) and at least a portion of the substrate. The relaxation of strain in areas of the semiconductor channel structure(s) adjacent to the diffusion break is reduced or avoided, because the semiconductor channel structure(s) is constrained by the surrounding structure.