A superparamagnetic solid catalyst has been successfully synthesized by loading palladium nanoparticles into the pore network of a mesoporous NiFe2O4 support (Pd/NF300), which was used as a magnetically separable and highly active catalyst for Suzuki and Heck C-C coupling reactions. Various techniques were employed to characterize the synthesized NiFe2O4 supports and Pd-loaded catalysts. The Pd/NF300 catalyst showed high activity for both Suzuki and Heck reactions even under a very low Pd using amount (0.08 mol% Pd based on aryl halide). Moreover, the catalyst could be magnetically separated, recycled, and showed a very slight reduction in catalytic activity after five cycles. A synergetic catalytic effect between the well dispersed Pd and the basic mesoporous structure of magnetic supports has been proposed to understand its greatly enhanced catalytic activities. (C) 2010 Elsevier B.V. All rights reserved.