The article introduces Fast-Cat, a self-driving catalysis laboratory designed for autonomous and resource-efficient parameter space navigation and Pareto-front mapping of high-temperature, high-pressure, gas–liquid reactions. Fast-Cat enables rapid ligand benchmarking and multi-objective catalyst performance evaluation with minimal human intervention. Specifically, the authors use Fast-Cat to identify the Pareto front for the hydroformylation reaction between syngas (CO and H₂) and olefin (1-octene) using rhodium and various phosphorus-based ligands. The system demonstrates its capabilities by swiftly identifying the Pareto front for different ligands within a short period of continuous autonomous experimentation. The article also highlights the generation of high-quality experimental data used to construct a digital twin of the homogeneous catalytic reaction, which aids in understanding the underlying reaction mechanism. The insights gained from Fast-Cat's investigations offer avenues for exploring new ligands, optimizing catalyst performance, and advancing the field of homogeneous hydroformylation.The article introduces Fast-Cat, a self-driving catalysis laboratory designed for autonomous and resource-efficient parameter space navigation and Pareto-front mapping of high-temperature, high-pressure, gas–liquid reactions. Fast-Cat enables rapid ligand benchmarking and multi-objective catalyst performance evaluation with minimal human intervention. Specifically, the authors use Fast-Cat to identify the Pareto front for the hydroformylation reaction between syngas (CO and H₂) and olefin (1-octene) using rhodium and various phosphorus-based ligands. The system demonstrates its capabilities by swiftly identifying the Pareto front for different ligands within a short period of continuous autonomous experimentation. The article also highlights the generation of high-quality experimental data used to construct a digital twin of the homogeneous catalytic reaction, which aids in understanding the underlying reaction mechanism. The insights gained from Fast-Cat's investigations offer avenues for exploring new ligands, optimizing catalyst performance, and advancing the field of homogeneous hydroformylation.