A new magnetic nanoparticle-supported N-heterocyclic carbene-palladium(II) nanomagnetic catalyst was synthesized and appropriately characterized using attenuated total reflectance infrared spectroscopy (ATR-IR), ultraviolet-visible spectroscopy (UV-Visible), inductively coupled plasma-atomic emission spectroscopy (ICP-AES), energy-dispersive X-ray spectroscopy (EDS), field-emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), X-ray powder diffraction (XRD), thermogravimetric analysis (TGA) and Brunauer-Emmett-Teller surface area analysis (BET). The nanomagnetic catalyst was used as convenient and efficient catalyst for the Suzuki-Miyaura cross-coupling reaction of various aryl bromides/chlorides/iodide with phenylboronic acid. The effects of varying solvents, bases, temperature, time and catalytic ratios on the performance of the Suzuki-Miyaura cross-coupling reaction were investigated. The notable advantages of this heterogeneous nanomagnetic catalyst are excellent yields, mild reaction conditions, short reaction times and easy work-up. Moreover, the new nanomagnetic catalyst could be easily recovered with an external magnet and could be reused at least five times without loss of its catalytic activity.