Homogenous Grubbs-type pre-catalysts have played an important role in the application of olefin metathesis to organic synthesis. Grafting of these homogeneous catalysts onto solid supports can aid catalyst recycling and removal of metallic residues from the product stream by filtration. In this paper we describe the reversible immobilization of a quaternary ammonium Hoveyda-Grubbs olefin metathesis pre-catalyst on sulphonic acid-functionalised silica-coated iron oxide magnetic particles. Following ring closing metathesis, the catalyst can be removed from the reaction via a magnet for reuse and/or regeneration.