In 1939 Ruth Palmer became the "County Librarian," reporting to Perrie Jones, the head of the Saint Paul Public Library. The Ramsey County Public Library was officially established in 1951 when the Board of Ramsey County Commissioners appointed the first Library Board. Service was provided through a bookmobile and several small outlets.

As growth in Roseville and the surrounding suburbs mushroomed, a new headquarters library was built on the corner of County Road B and Hamline in 1964. Full-service libraries were built in Maplewood in 1967 and Arden Hills in 1969. The village library in White Bear Lake merged with the County in 1967 followed by North Saint Paul in 1972. New libraries were built in those communities in 1974 and 1977 respectively.

Ruth Palmer retired as director at the end of 1969 having served thirty years. As of January 1, 1970, the staff consisted of 32 full-time and 35 part-time employees. Phyllis Olmen was acting director until Nowell Leitzke started in the fall of 1970. Mr. Leitzke resigned in 1971. The Library Board then selected Norman Vinnes as director.

The borrowing of books and other library materials increased by 129% during the 1970s, reaching a total of 1,302,414 in 1979. The Friends of the Suburban Ramsey County Libraries were formed in 1979 to advocate for better library funding. The Friends, with nearly 400 members, focused much of their energy on running a used book store at the Maplewood Library and holding an annual used book sale in September at the library in Roseville. Money they raise is donated to the Library.

The Roseville Library was remodeled in 1981 to accommodate increased use. In 1986, the library's first computer system was brought online to handle lending transactions and catalog records.

Because of growing communities and increasing use, the Library Board developed a plan for expanded and new facilities. The result was a $15,000,000 bonding program for a new library in Mounds View in 1990 and Shoreview in 1992. The bonds also financed the rebuilding of the Maplewood and Roseville libraries in 1993.

When Norm Vinnes retired in 1993, he was succeeded by Marianne Roos who served as Library Director until 1999. During Roos's tenure the library saw substantial increases to the book budget and additional open hours, including Sunday hours. Roos launced the Dunn Bros. Coffee Shop at the library in Roseville, the first such library venture in the state. When Roos left in 1999, Alice-Jo Carlson served as interim director and was chosen as the new library director in September 2000. Carlson instituted alternative revenue projects, such as the Booker™ Literacy Project and Licensing Program, a line of merchandise and the partnerships with cities within the Library's service area. Circulation of library materials increased by more than 30% from 2000 to 2005.

When state and county budgets were reduced in 2003, the Ramsey County Library suspended service at the library in North Saint Paul to meet the reductions. Alice-Jo Carlson retired in January of 2005, and Susan Nemitz was appointed director.

In March of 2005, a library was opened in the North St. Paul Community Center. County, city and library officials partnered to develop this innovative plan. Other branches in the Ramsey County Library system include Arden Hills, Maplewood, Mounds View, Roseville, Shoreview and White Bear Lake.

The library system is governed by a seven-member Library Board appointed by Ramsey County Board of Commissioners. The Library's annual budget is around $7.8 million with the majority of funding coming from suburban Ramsey County property tax revenue. The equivalent of 105 full-time employees work at the Library.

More than 1.6 million people visit the Library annually. Customers are now also making hundreds of thousands of remote electronic connections to the library catalog, web site, and databases.