Arup Group Limited is a multinational professional services firm headquartered in London, UK which provides engineering, design,planning, project management and consulting services for all aspects of the built environment. The firm is present in Africa, the Americas, Australasia, East Asia, Europe and the Middle East, and has over 10,000 staff based in 92 offices across 42 countries. Arup has participated in projects in over 160 countries.

Arup is owned by trusts, the beneficiaries of which are Arup's past and present employees, who receive a share of the firm's operating profit each year.

The firm was founded in London in 1946, as the Ove N. Arup Consulting Engineers by Sir Ove Nyquist Arup. Sir Ove set out to build a firm where professionals of diverse disciplines could work together to produce projects of greater quality than was achievable by them working in isolation. In 1963, together with the architect Philip Dowson, Arup Associates was formed to offer multi-disciplinary architectural and engineering services. In 1970, the firm reformed as "Ove Arup & Partners" and, in the same year, Ove Arup delivered "The Key Speech", setting out values and a future vision for Arup.