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Electric-field control of magnetic resonance has application potential in the design of low-power, compact, high-frequency magnetoelectronic devices, such as microwave filters and circulators. To date, this work has exploited low-loss ferrite materials mechanically coupled to piezoelectric substrates. However, traditional ferrites typically require lattice-matched substrates and extreme growth conditions to produce high-quality material, making on-chip integration while maintaining low damping a significant challenge. Here, we demonstrate electric-field control of the FMR properties of the low-loss (α = (3.98 ± 0.22) × 10^-5), organic-based, room-temperature ferrimagnet vanadium tetracyanoethylene (V[TCNE]_x≈2) in V[TCNE]_x/piezoelectric composite heterostructures. These structures show shifts in the resonant frequency position by ~50 MHz, or more than six times the resonant linewidth. These results demonstrate the potential of V[TCNE]_x to complement traditional ferrites in electrically-controlled magnetoelectronic devices. For example, since V[TCNE]_x can be deposited on a variety of inorganic substrates, it has the potential to be directly integrated into magnetoelectric devices without the need for flip-chip fabrication techniques.