2121 Sevastopol was discovered by D. Higgins, P. Pravec, P. Kusnirak, J. Pollock, J. Oey, M. Husarik, G. Cervak, D. E. Reichart, K. M. Ivarsen, J. B. Haislip, and A. LaCluyze on July 23, 2010.
Its minor-planet moon was discovered in 2010. 2121 Sevastopol T. Smirnova 27 June 1971 
