Born in Paris, France, Debierne was educated at the Ecole de Physique et Chemie. After graduation he worked at the Sorbonne and as an assistant to Pierre and Marie Curie, finally succeeding the latter as director of the Radium Institute. On his retirement in 1949 he in turn was succeeded by Marie Curie's daughter, Irène Joliot-Curie.

Debierne was principally a radiochemist; his first triumph came in 1900 with the discovery of a new radioactive element, actinium, which he isolated while working with pitchblende. In 1905 he went on to show that actinium, like radium, formed helium. This was of some significance in helping Ernest Rutherford to appreciate that some radioactive elements decay by emitting an alpha particle (or, as it turned out to be, the nucleus of a helium atom). In 1910, in collaboration with Marie Curie, he isolated pure metallic radium.