Samarium was observed spectroscopically by Jean Charles Galissard de Marignac, a Swiss chemist, in a material known as dydimia in 1853. Paul-Émile Lecoq de Boisbaudran, a French chemist, was the first to isolate samarium from the mineral samarskite ((Y, Ce, U, Fe)₃(Nb, Ta, Ti)₅O₁₆) in 1879. Today, samarium is primarily obtained through an ion exchange process from monazite sand ((Ce, La, Th, Nd, Y)PO₄), a material rich in rare earth elements that can contain as much as 2.8% samarium.

Samarium is one of the rare earth elements used to make carbon arc lights which are used in the motion picture industry for studio lighting and projector lights. Samarium also makes up about 1% of Misch metal, a material that is used to make flints for lighters.

Samarium forms a compound with cobalt (SmCo₅) which is a powerful permanent magnet with the highest resistance to demagnetization of any material known. Samarium oxide (Sm₂O₃) is added to glass to absorb infrared radiation and acts as a catalyst for the dehydration and dehydrogenation of ethanol (C₂H₆O).