Many refineries use hydrogen to upgrade heavy fuel feedstocks, and therefore, hydrogen solubility is an important parameter. Shale oil is a fuel for which hydrotreatment is of interest, but no data about its hydrogen solubility can be found in the literature. This Article presents experimental data for the hydrogen solubility of two shale oil samples measured at high temperatures and pressures (423-527 K and 40-140 bar). Experiments were performed using a continuous flow apparatus. Results show that the shale oil had a lower hydrogen solubility than most other fuels, probably due to the high content of polar phenolic compounds in the oil. Removing about 80% of the phenolic compounds increased the hydrogen solubility by approximately 0.1 mol H-2/kg oil (which is about 15 to 45%, depending on the solubility). Analysis also showed that current prediction methods used for petroleum and coal liquids cannot reliably be used for predicting the hydrogen solubility of this shale oil and other similar fuels.