Rubidium selenide is an inorganic compound composed of selenium and rubidium. It is a selenide with a chemical formula of Rb₂Se. Rubidium selenide is used together with caesium selenide in photovoltaic cells.

Rubidium selenide can be prepared by reacting mercury selenide and metallic rubidium. The elements can be synthesized in liquid ammonia.

Hydrogen selenide can also be dissolved in an aqueous solution of rubidium hydroxide to eventually form rubidium selenide. This method is similar to the method for preparing rubidium sulfide, because they are both chalcogenide compounds.

Rubidium selenide has cubic crystal structure, which belongs to the antifluorite structure, and the space group is ${\displaystyle Fm{\bar {3}}m}$ and the lattice parameters are a=801.0 pm, per unit. The unit cell has 4 units.