Clinton is scheduled to attend a rally with Markey on Saturday at Worcester Polytechnic Institute. Sen. Elizabeth Warren is also expected to attend.
Markey faces Republican Gabriel Gomez in the June 25 special election to fill the Senate seat left vacant when John Kerry became Secretary of State.
Clinton, still a popular figure in the Democratic Party, is among a list of high-profile Democrats lending their support to Markey. President Barack Obama stumped for him Wednesday.
Gomez, meanwhile, has what he is calling a Latino Town Hall planned for Saturday in Southbridge. It’s one of a series of town halls leading up to election day.