The Mercer County Library serves 160,000 residents in the city of Lawrenceville and Mercer County. The system consists of nine branches: 
Ewing, Hickory Corner, Hightstown, Hollowbrook, Hopewell, Lawrence, Robbinsville, Twin Rivers, and West Windsor. The library system maintains approximately 672,380 volumes and circulates 1.9 million items per year. The library locations provide meeting rooms, notary, remote printing services, scanning, and interlibrary loans. It also offers programs such as summer reading, storytime, babytime, family craft, book clubs, computer classes, and English learning.