Polyether-ether-ketone　(PEEK)　exhibits　excellent　mechanical　properties　and　biocompatibility.　Three-dimensional　(3D)　printing　of　PEEK　bone　substitutes　has　been　widely　used　in　clinical　application.　However,　the　inertness　of　pure　PEEK　hinders　its　integration　with　the　surrounding　bone　tissue.　In　this　study,　for　the　first　time,　PEEK/hydroxyapatite　(HA)　composite　specimens　were　fabricated　using　fused　filament　fabrication　(FFF)　technology.　PEEK/HA　filaments　with　HA　contents　of　0–30　wt%　were　fabricated　via　mechanical　mixing　and　extrusion.　The　HA　distributions　inside　the　composite　matrix　and　the　surface　morphology　characteristics　of　the　PEEK/HA　composites　were　examined.　The　effects　of　the　printing　path　and　HA　content　on　the　mechanics　of　the　PEEK/HA　composites　were　systematically　investigated.　The　results　indicated　that　the　HA　particles　were　uniformly　distributed　on　the　composite　matrix.　With　an　increase　in　the　HA　content,　the　modulus　of　the　PEEK/HA　composite　increased,　while　the　strength　and　failure　strain　concomitantly　decreased.　When　the　HA　content　increased　to　30　wt%,　the　tensile　modulus　of　the　composite　increased　by　68.6%　compared　with　that　of　pure　PEEK　printed　along　the　horizontal　90°　path,　while　the　tensile　strength　decreased　by　48.2%　compared　with　that　of　pure　PEEK　printed　along　the　vertical　90°　path.　The　fracture　elongation　of　the　printed　specimens　with　different　HA　contents　decreased　in　the　following　order:　horizontal　0°　＞　horizontal　90°　＞　vertical　90°.　The　best　comprehensive　mechanical　properties　were　achieved　for　pure　PEEK　fabricated　along　the　horizontal　0°　path.　The　results　indicate　that　FFF　technology　is　applicable　for　additive　manufacturing　of　PEEK/HA　composites　with　controllable　compositions.　Printed　PEEK/HA　composites　have　potential　for　applications　in　the　design　and　manufacturing　of　personalized　bone　substitutes.　©　2021