Transition　metal　chalcogenides　quantum　dots　(TMCs　QDs)nanocrystalsare　featured　by　large　absorption　coefficient,　abundant　active　sites,and　quantum　confinement　effect,　rendering　them　emerging　light-harvestingantennas　for　solar　energy　conversion.　Although　diverse　TMCs　QDs-basedphotosystems　have　been　explored　for　multifarious　photoredox　catalysis,an　elaborate　and　comprehensive　summary　on　TMCs　QDs-based　solar-to-hydrogenconversion　has　been　rarely　reviewed.　In　this　Review,　we　elucidatethe　fundamental　physicochemical　properties　of　TMCs　QDs　(e.g.,　CdSQDs,　CdSe　QDs,　CdTe　QDs,　etc.)　currently　being　extensively　investigatedalong　with　synthesis　methodologies.　Modification　strategies　for　boostingphotocatalytic　water　splitting　performances　of　TMCs　QDs,　such　as　cocatalystloading,　heterojunction　engineering,　element　doping,　and　plasmonicmetal　photosensitization,　are　then　specifically　introduced.　Besides,we　present　detailed　information　on　the　latest　advances　on　the　photocatalytichydrogen　generation　involving　sacrificial　reagents,　Z-scheme　photosystems,one-step　excitation　photosystems　for　overall　water　splitting,　andphotosensitizers　endowed　by　molecular　catalysts,　metal-organicframeworks,　or　conjugated　polymers.　Finally,　future　outlook　and　challengeon　the　development　of　TMCs　QDs-dominated　photocatalysis　are　highlighted.It　is　anticipated　that　our　Review　would　inspire　ongoing　interest　inunleashing　the　great　potential　of　TMCs　QDs　nanocrystals　for　solarenergy　conversion.