Well-dispersed palladium nanoparticles (Pd NPs) supported on amine-functionalized, mixed-linker metal–organic frameworks (MIXMOFs) based on MIL-53(Al) were prepared by using the ion-exchange method. Pd NPs were characterized by powder X-ray diffraction (XRD), N2 adsorption, transmission electron microscopy (TEM), inductively coupled plasma atomic emission spectroscopy (ICP-AES), and X-ray photoelectron spectroscopy (XPS). The mean diameter of Pd NPs is approximately 3.2 nm. It was found that the Pd NPs supported on amine-functionalized MIXMOFs are stable at high temperature. The Pd NPs exhibit efficient catalytic activity for Heck reaction and can be easily recovered and reused.