We use time-domain thermoreflectance (TDTR), and the generation and detection of longitudinal and surface acoustic waves, to study the thermal conductivity, heat capacity, and elastic properties of thin films of poly­(vinyl alcohol) (PVA), poly­(acrylic acid) (PAA), polyacrylamide (PAM), poly­(vinyl­pyrrolidone) (PVP), methyl cellulose (MC), poly­(4-styrene­sulfonic acid) (PSS), poly­(N-acryloyl­piperidine) (PAP), poly­(methyl methacrylate) (PMMA), and a polymer blend of PVA/PAA. The thermal conductivity of six water-soluble polymers in the dry state varies by a factor of ≈2, from 0.21 to 0.38 W m–1 K–1, where the largest values appear among polymers with a high concentration of hydrogen bonding (PAA, PAM, PSS). The longitudinal elastic constants range from 7.4 to 24.5 GPa and scale linearly with the shear elastic constants, suggesting a narrow distribution of Possion’s ratio 0.35 < ν < 0.40. The thermal conductivity increases with the average sound velocity, as expected based on the model of the minimum thermal conductivity. The thermal conductivity of polymer blends of PVA (0.31 W m–1 K–1) and PAA (0.37 W m–1 K–1) is in agreement with a simple rule of mixtures.