The 1925 Workers' Summer Olympiad was the second edition of International Workers' Olympiads. The games were held from July 24 to July 28 at Frankfurt am Main in Germany.

International Workers' Olympiads were an international sporting event arranged between 1925 and 1937 by Socialist Workers' Sport International (SASI). It was an organisation supported by social democratic parties and International Federation of Trade Unions. Workers' Olympiads were an alternate event for the Olympic Games. The participants were members of various labor sports associations and came mostly from Europe. Nowadays the CSIT World Sports Games are the successor sports events of the International Workers' Olympiads. The "World Sports Games" is the main highlight and a new brand of the International Workers and Amateurs in Sports Confederation (CSIT). It is a sports event for thousands of workers and amateurs held every two years. The CSIT is an international multi-sports organization.