The mobility of dislocations and their interaction with interfaces in nanocrystal and multilayers affect the mechanical behaviors of the material, depending on material compositions and interface conditions. In this paper, a semi-analytical solution is developed for calculating the elastic fields of dislocation loops within isotropic bimaterials with linear springlike imperfect interface models. Calculation examples of dislocation loops within Al–Cu bimaterials are performed, which demonstrate the reliability of the semi-analytical approach. The effects of constant matrix on the interface elastic fields are studied, showing that the interface constant matrix can influence the elastic fields drastically. Comparisons between perfect bonding and imperfect interface models are performed to study the effects of interface imperfection conditions on the in-plane and out-of-plane elastic fields across the bimaterial interface plane.