Deuterium, as hydrogen tracer, has been used in this study to investigate the nature of the hydrogen trapping in High Strength Steels that contain retained austenite. While it is well known that austenite exhibits a low hydrogen diffusivity and high hydrogen solubility, questions remain on the characteristics of hydrogen trapping by the retained austenite. For this study, a generic Quenching and Partitioning “Q&P” alloy was used. The deuterium was introduced in the material at high temperatures during the simulation of a typical Q&P annealing cycle. This procedure allowed to perform a qualitative study of the hydrogen trapping by the retained austenite. The results proved that the hydrogen is strongly bound to the retained austenite and/or to the α’/γ interface when it is introduced during the high temperature annealing cycle.