This dataset contains mean Raman spectra of polyethylene glycol (PEG) samples covering a typical range of molecular weights. The spectra were obtained under standardized measurement conditions and are provided as normalized raw mean spectra and pre-processed mean spectra in separate worksheet tabs. Raman spectra were acquired using a confocal Raman microscope with 633 nm laser excitation. Measurements were performed on defined, dried PEG droplets deposited on stainless steel substrates under standardized acquisition conditions. All samples were measured using identical instrumental settings to ensure comparability across molecular weights. For each PEG molecular weight, mean spectra are provided separately for calibration and validation subsets, reflecting independent spectral averages derived from distinct measurement sets. The dataset is intended for transparent data sharing and documentation of representative Raman spectral profiles of PEG. PEG samples are labeled using a shorthand notation (e.g., 01k, 02k, 06k), where the number indicates the nominal molecular weight in kilograms per mole (01k=1 kg/mol; 35k= 35 kg/mol).