Binary mixtures of ethylene glycol and water are widely used as working fluids in many areas, and the study of thermal conductivity is crucial in the determination of the heat transfer properties of related systems. In this paper, the thermal conductivity of these binary mixtures at a series of ethylene glycol concentrations (0 to 100 wt%) is measured experimentally using a transient hot-wire system at evaluated temperature and pressure range from 293–533 K and 0.1–15.0 MPa. Moreover, the experimental data are fitted into an equation as a function of temperature, pressure, and concentration, the average absolute deviation and maximum deviation between fitted values and experimental data are 0.29 % and 1.05 %, respectively, which shows that this equation describes our data very well. Furthermore, available experimental data in the literature are collected and the comparisons between literature data and our data are analyzed, our data agree well with most literature data. This work is expected to promote the use of binary mixtures of ethylene glycol and water as heat transfer working fluids in industries.