G4S is a British multinational private security company headquartered in London, England. Established in July 2004 through the merger of Securicor and Group 4 Falck, G4S has grown to become one of the world’s largest security firms, operating in over 90 countries and employing more than 533,000 people as of 2021.

In April 2021, G4S was acquired by Allied Universal, a U.S.-based security services provider, in a £3.8 billion deal. This acquisition aimed to create a leading integrated security business with projected revenues of approximately $18 billion.

G4S offers a comprehensive range of services, including manned security, cash handling, justice services, and outsourced business processes related to security and safety risks . In Tanzania, G4S provides various security solutions such as security systems and services, cash solutions, and risk management and consulting services.​