Ethyl nonanoate is a promising component of biodiesel with a satisfactory cetane number and reactivity. The speeds of sound in ethyl nonanoate were measured by the Brillouin light scattering (BLS) method within the temperatures from 295.24 to 593.15 K and at pressures up to 10 MPa. The relative expanded uncertainty (k = 2) of our BLS experimental system is estimated to be less than 0.7%. The densities of ethyl nonanoate were measured using a vibrating tube densimeter at atmospheric pressure in the temperature range of 293.15-353.15 K, and the absolute average relative deviation between the experimental densities and the literature data is 0.12%. For temperatures between 303.15 and 353.15 K and at pressures up to 10 MPa, these measurements were used to calculate densities, isobaric heat capacities, and indirect derivative properties including the isobaric thermal expansion, the isothermal compressibility, the isentropic compressibility, and the internal pressure. The comparison between the calculated isobaric heat capacities and the literature values shows a satisfactory agreement with an absolute average relative deviation of 0.18% and a maximum deviation of 0.38%. At the end, the dependences of internal pressure of ethyl nonanoate on temperature and pressure were found to be in accordance with those of ethyl caprylate and ethyl caprate.