The four-year contract has an estimated value to the JV of approximately QAR151.6m (£28.8m). Hill is a 50% partner in the joint venture.
The 38.5km tram system will have four lines, 25 at-grade stations and seven underground stations.
"This project will have a major impact on Lusail City and its position as a prominent business and leisure destination in Qatar," said Mohammed Al Rais, regional president (Middle East) for Hill's project management group.
Lusail City, just north of Doha, is a waterfront development currently under construction. It is designed to be an environmental and self-sustaining community. The city will have residential and commercial developments together with schools, medical facilities, shopping centres, and more.