The activities of IRO are centred around the promotion of inter-faith understanding and services which includes:

Seminars / Public Talks
The IRO conducts seminars and public talks at regular intervals for increasing general awareness about the common beliefs that underlie all our religions and how they contribute to peace and harmony in Singapore.

Voluntary Services
The IRO attempts to encourage members of its constituent inter-faith group to participate in public campaigns for organ donation, engage in voluntary work for in rehabilitation programmes for drug addicts, the disadvantaged young, the needy and the elderly.

The IRO also initiates inter-faith co-operation in welfare service projects as well as community service campaigns.

Inter-Faith Prayer Services
Inter-faith prayer services are also organised by the IRO for public institutions, civic organisations and private enterprises that request for inter-faith devotional services. These include inter-faith prayer services for SAF officer cadet passing out parades, opening ceremonies of buildings, public works and construction projects. The IRO has also been called upon to organise inter-religious memorial services for the victims of unfortunate public tragedies such as the SilkAir Crash in Palembang and the SQ006 crash in Taipei.

Inter-Faith Fellowship
For further strengthening community bonds, members also regularly attend the religious festivals and ceremonies organised by fellow IRO members and outside bodies. The holding of the World Religion Day and IRO Day observance each year have become important inter-faith peace and harmony events in Singapore. Since 1996, IRO has annually organized National Day observances that bring peoples of different religions to celebrate the National Day together.

Publications
Since founding in 1949, the IRO has also published three editions of its popular Religions in Singapore publication and IRO-40, its 40th Anniversary Commemorative Book. It also brings out booklets and in-house bulletins, brochures as well as several papers on religious harmony and spiritual values in the modern age for its members and the public from time to time.

Collating of Inter-Religious Views
The IRO is also invited from time to time to collate inter-religious submissions and views to the Parliamentary Select Committee and Bioethics Advisory Committee on issues dealing with morality and related spiritual matters of concern to Singapore.