Engineers will replace worn out tram tracks along the Supertram route as part of the next stage of improvements to the service.
Work begins on March 29 in Hillsborough and Malin Bridge.
The new rails, made from harder-wearing steel, will last for 25 to 30 years. Work is set to be complete by September.
Some delays are expected but bus replacement services will be in operation to minimise disruption.
David Young, of the South Yorkshire Passenger Transport Executive, which is funding the work alongside Stagecoach Supertram, said: “The tram is a great way to travel around Sheffield, but this work is essential to the future operation of the system and the benefits it brings to the region.
“During the work, there will be some short-term disruption for some tram users, residents and businesses, and we would like to thank everyone in advance for their patience and understanding. Once the project is completed, everyone travelling in Sheffield will benefit.”
The work being carried out will be aligned with the planned tram train pilot project. The project, which is expected to be in operation by 2016, will see a new tram train link between Sheffield and Rotherham.