A swing bearing allows a reduction in thickness, weight, and manufacturing cost by fixing together a pair of split rings each formed of a plate member to form an outer ring, and fixing together a pair of split rings each formed of a plate member to form an inner ring. The outer ring is composed of a pair of split rings which are obtained by splitting the outer ring at an axially midpoint of the first raceway groove, are formed of respective plate members, and are fixed together. The inner ring is composed of a pair of split rings which are obtained by splitting the inner ring at an axially midpoint of the second raceway groove, are formed of respective plate members, and are fixed together.