Reconstructing the thermal history of sedimentary basins informs how regional tectonics impacts hydrocarbon exploration and production. Here, we apply Raman spectroscopy of carbonaceous material (RSCM) on well cuttings retrieved from organic-rich Ordovician through Permian intervals to investigate the peak temperature experienced by strata in the Delaware Basin of western Texas. We compare new results from RSCM thermometry against vitrinite reflectance and Rock-Eval pyrolysis results and assess spatial patterns of peak temperatures and reconstruct paleogeothermal gradients for the sampled depth interval. New RSCM results from this study demonstrate that the western portion of the Delaware Basin experienced peak temperatures up to 100°C higher than equivalent depths in the eastern portion of the basin, consistent with existing vitrinite reflectance measurements. The paleogeothermal gradient profiles from 11 wells in Reeves and Loving Counties, Texas, including a well that intersected an igneous intrusion, show that reconstructed peak geothermal gradients from the sampled depth interval vary across the basin from approximately 40–45°C/km in the east and up to 77°C/km in the west. Higher geothermal gradients in the west correspond to areas with poor agreement between RSCM and vitrinite reflectance and are situated close to Cenozoic igneous centers. This study highlights the viability of RSCM in sedimentary basins across a range of peak temperatures spanning approximately 60–260°C and emphasizes the likely combined roles of long-term geologic burial and punctuated volcanic phases on the thermal history and source rock maturation in the Delaware Basin.