This is a list of the largest radio galaxies currently discovered arranged by size. This list will include radio galaxies over 10 million light years across, equivalent to approximately 3 megaparsecs.
Radio galaxies with radio lobes (also known as radio emissions) that extend further than 2.3 million light years or 0.7 megaparsecs in length are classified as giant radio galaxies, also referred as GRGs. Giant radio galaxies that contain quasars in their galactic centers are commonly called giant radio quasars, also known as GRQs.
A radio galaxy is a type of galaxy with vast areas of radio emissions stretching far beyond the apparent structure. The powerful radio lobes are generated by the jets from the active galactic nucleus. The very luminous galactic center known as the active galactic nucleus (AGN) is usually powered by a supermassive black hole.
Below is the list of the largest radio galaxies known, with diameters of over 9.7 million light years or 3 megaparsecs. The radio lobes are usually measured using the total angular diameter and the distance of the host galaxy.
Listed below are superlative giant radio galaxies under 9.7 million light years or 3 megaparsecs in diameter.