The increasing integration of renewable and low-emission energy technologies into modern power systems has introduced new dynamic interactions that can significantly affect power-system stability. In particular, the simultaneous operation of Solid Oxide Fuel Cell (SOFC) power plants and Doubly Fed Induction Generator (DFIG)-based wind turbines with conventional synchronous generators creates a hybrid generation structure whose small-signal dynamic characteristics require comprehensive investigation. This paper investigates the small-signal stability of a power system in which an SOFC power plant and a DFIG-based wind turbine operate in parallel with a synchronous generator. To this end, a comprehensive mathematical model of the SOFC generation unit and the DFIG-based wind turbine is developed and integrated into a single-machine infinite-bus (SMIB) power-system configuration. The resulting nonlinear dynamic model represents the principal interactions among the conventional synchronous generator, SOFC unit, wind-energy conversion system, and the associated control and electrical components. The mathematical models are subsequently linearized around a selected operating point to obtain an appropriate small-signal representation of the integrated system. Based on the linearized model, a modified Heffron–Phillips model corresponding to the proposed generation configuration is derived, providing a systematic framework for evaluating the dynamic behavior and stability characteristics of the system. Small-signal stability is then assessed by examining the effects of the integrated SOFC and DFIG units under different system parameters and operating conditions. The results indicate that the integration of these generation technologies can alter the dynamic stability characteristics of the power system in both favorable and unfavorable ways. The magnitude and direction of these effects depend strongly on system parameters and operating conditions, highlighting the importance of considering the dynamic interactions between conventional and emerging generation technologies when assessing power-system stability. The proposed modeling and analytical framework can provide a useful basis for stability assessment and for the coordinated integration of SOFC and DFIG-based generation into future power systems.