Satellite-estimated　solar-induced　chlorophyll　fluorescence　(SIF)　is　proven　to　be　an　effective　indicator　for　dynamic　drought　monitoring,　while　the　capability　of　SIF　to　assess　the　variability　of　dryland　vegetation　under　water　and　heat　stress　remains　challenging.　This　study　presents　an　analysis　of　the　responses　of　dryland　vegetation　to　the　worst　extreme　drought　over　the　past　two　decades　in　Australia,　using　multi-source　spaceborne　SIF　derived　from　the　Global　Ozone　Monitoring　Experiment-2　(GOME-2)　and　TROPOspheric　Monitoring　Instrument　(TROPOMI).　Vegetation　functioning　was　substantially　constrained　by　this　extreme　event,　especially　in　the　interior　of　Australia,　in　which　there　was　hardly　seasonal　growth　detected　by　neither　satellite-based　observations　nor　tower-based　flux　measurements.　At　a　16-day　interval,　both　SIF　and　enhanced　vegetation　index　(EVI)　can　timely　capture　the　reduction　at　the　onset　of　drought　over　dryland　ecosystems.　The　results　demonstrate　that　satellite-observed　SIF　has　the　potential　for　characterizing　and　monitoring　the　spatiotemporal　dynamics　of　drought　over　water-limited　ecosystems,　despite　coarse　spatial　resolution　coupled　with　high-retrieval　noise　as　compared　with　EVI.　Furthermore,　our　study　highlights　that　SIF　retrieved　from　TROPOMI　featuring　substantially　enhanced　spatiotemporal　resolution　has　the　promising　capability　for　accurately　tracking　the　drought-induced　variation　of　heterogeneous　dryland　vegetation.