The Main Branch of the Union County Public Library is in Monroe, NC. The Monroe Library reopened in March 2003 after it was renovated and expanded. The library has 34,000 SF with over 81,000 items, including books, DVDs, videos, books on tape and CD, young adult books, genealogy, CDs, CD-ROMs, magazines, newspapers and more. There are 37 computers for adults, 4 computers for young adults and four computers for children, in addition to seven online public access computers. There are six study rooms for adult, two study rooms for children and young adults, a genealogy room, a toddler area, a young adult area, and two meeting rooms.

The Monroe Library serves Monroe and the central region; it also serves as the Main Library.