<p>The aim of this work was to investigate and analyse the feasibility of pyrolytic tyre char (PT-char) as filler in polypropylene (PP) composites. Untreated PT-char was first demineralised with acid-base lixiviants (nitric acid and sodium hydroxide) to remove impurities. Thereafter, surface modification was done using either 3-methacryloxypropyletrimethoxysilane (3-MPTS) or titanium IV 2,2 (bis-2-propenolatomethyl) butanolato, tris (dioctyl) pyrophosphato-O (LICA 12) coupling agents, or maleic anhydride-grafted polypropylene (MAgPP) compatibiliser to improve surface compatibility. PP composites filled with varying amounts of unmodified or modified PT-char were produced following which impact strength, surface fracture and tensile properties were tested to evaluate the feasibility of using PT-char as filler. Unmodified PT-char showed moderate improvements in some mechanical properties. On the other hand, demineralisation of PT-char generally reduced the mechanical properties. Surface modification with 3-MPTS and LICA 12 improved the mechanical properties of PP composites due to enhancement of the interface between PT-char and the PP matrix. High PT-char loadings reduced the mechanical properties of PP composites particularly with demineralised PT-char, presumably due to aggregation of small particles which caused defects in the composites system. PT-char demonstrated good potential for use as a filler in PP composites; however, application of a suitable surface modifier is imperative to enhance compatibility between the PT-char and the PP matrix and reduce the impact of aggregation of the PT-char particles. A technically feasible solution was presented for valorisation of waste PT-char, while simultaneously enhancing the mechanical properties of everyday PP composites. </p>