RSK Group is a UK-based environmental, engineering, and technical services company founded in 1989 by Alan Ryder. Headquartered in Helsby, Cheshire, it has grown to encompass over 200 companies and approximately 14,500 employees, with a turnover of �1.9 billion as of 2024. The company aims to become Europe's largest privately owned environmental and engineering business, with plans for international expansion across multiple continents and a target of 40,000 employees by 2030.

The company provides a wide range of services, including environmental science and research, engineering design, environmental impact assessments, energy transformation consulting, and health and safety management. RSK primarily serves clients in the energy sector, construction, and design industries, focusing on helping organizations manage their environmental and social impacts while ensuring compliance with regulations. With a strong acquisition strategy, RSK has acquired over 70 businesses between 2016 and 2022, positioning itself for continued growth in the environmental consultancy market.