A fiber optical adapter includes a base body and a base element. The base body includes a receiving groove. Two ends of the base body form insertion openings respectively communicating with the receiving groove. The base element is in the receiving groove. The base element includes a first connection member, a second connection member combined with the first connection member, and socket members. Each socket member is received in the corresponding first sleeve member of the first connection member and the corresponding second sleeve member of the second connection member.