The Morgan County Public Library's main branch is located in Martinsville just a block from the courthouse square at the corner of Jefferson and Grant Streets. The original structure is a Carnegie library, constructed beginning in 1906. The library was expanded in 1990, and again recently in 2020. The new space is beautiful and includes a fun teen area as well as a sizeable area that can be used for programming and rented for private events. The Morgan County Library also has five branch locations located throughout the county.
The Monrovia Branch is located at 145 South Chestnut Street, with open hours six days per week.