One Great George Street (OGGS) is a four-domed grade II listed Edwardian building used as a conference and wedding venue just off Parliament Square in Westminster, London, England. The building is the global headquarters of the Institution of Civil Engineers (ICE); it was originally solely a venue for ICE members to meet informally and for conferences, but became available for public events in 1989. It is near the Houses of Parliament, Westminster Abbey, and St James's Park.

The Institution of Civil Engineers (ICE) is an independent professional association for civil engineers and a charitable body in the United Kingdom. Based in London, ICE has over 92,000 members, of whom three-quarters are located in the UK, while the rest are located in more than 150 other countries. The ICE aims to support the civil engineering profession by offering professional qualification, promoting education, maintaining professional ethics, and liaising with industry, academia and government. Under its commercial arm, it delivers training, recruitment, publishing and contract services. As a professional body, ICE aims to support and promote professional learning, managing professional ethics and safeguarding the status of engineers, and representing the interests of the profession in dealings with government, etc. It sets standards for membership of the body; works with industry and academia to progress engineering standards and advises on education and training curricula.