Provided is a glass composition that has a low reactivity with the constituent materials forming a solid oxide fuel cell while having a thermal expansion coefficient suitable for sealing a solid oxide fuel cell, and a glass composition and sealing material that are suitable for sealing a solid oxide fuel cell. The present invention, which relates to a sealing glass composition, is a sealing glass composition used for sealing a solid oxide fuel cell, characterized by having a composition ratio of, expressed in terms of oxide, 40 to 55% by mass of SiO2, 0 to 5.0% by mass of Al2O3, 0 to 8.0% by mass of B2O3, 20 to 30% by mass of MgO, and 10 to 24% by mass of CaO, wherein a total of the MgO and the CaO is 40 to 54% by mass.