1910 - Letters to the editor, meetings, editorials, support Library establishment.

1911 - By-law for provision of a Library to be known as the Lethbridge Public Library (and not by any other name).

1919 - First Library Board appointed: W. J. Nelson (Chair), H. W. Meech, Rev. C. E. Cragg
August 14th - Library service opened in two rooms at the Y.M.C.A. (NE corner 10th Street and 4th Avenue South).
First Librarians: A. N. Filmer, L. McIndoe and Arthur Frayne

1920 - Hazel Bletcher appointed Librarian.

1922, January 23rd - Carnegie Library opened (construction cost $26,996), Galt Gardens. Presently the Southern Alberta Art Gallery. Children's Library, Adult Library, Lecture Room.

1948 - Audio-Visual collection was initiated. Films-1948; Records-1949.

1951, November 4th - extension to Carnegie Library opened.

1952 - March-John Dutton appointed Chief Librarian.

1956-1974 - North Lethbridge Branch Library service.

1961-1974 - South Lethbridge Branch Library service.

1962 - Philip Rees Librarian.

1965 - George Dew Librarian.

1974 - New Library opens (present site-5th Avenue & 9th Street). Duncan Rand Librarian.

1985 - Bookmobile service is available.

1986 - Automated Library System plan initiated.

1989 - Library installs DYNIX automated system.
1992 - 20,000 sq. ft. extension completed to original building.
Chinook Arch Regional Library System formed.

1997 - Public internet access computers introduced.

1999 - Millennium Garden at the Lethbridge Public Library completed through the support of the Millennium Bureau of Canada.

2001 - Liz Rossnagel arrives as Director of the Lethbridge Public Library.

2003 - The Library opened the community's first Information Literacy Centre in partnership with the Lethbridge Community Network. A new website was launched allowing direct 24 hour/day, 7 day/week accessibility.

2005 - A partnership - Lethbridge School district #51, Holy Spirit Catholic Separate School division, Lethbridge Public Library Board and the City of Lethbridge - was formed to build a West Lethbridge Multi-Use Centre consisting of a public high school, a community branch of the Library, a campus of the Caholic High School and the City run recreational fields and parkland.

2006 - Lois Hole Memorial Garden, a joint project of the Library, Lethbridge and District Horticultural society and the City of Lethbridge, was opened.

2007 - A one-time Community Development Grant was used to transform the Main Library's South wing into Your Downtown Branch - it included the creation of the Page!Break Cafe.

2008 - Beverly Shimazaki assumed the role of Acting Director. An outdoor patio space was added to the Page!Break, now operated by Round^St Café.

2009 - Todd Gnissios accepted the position of Acting Director. The Library celebrated its 90th Anniversary in 2009 and kicked off a Branching Out Capital Campaign for The Crossings Branch Library, located in the new West Lethbridge Centre.

2010, February 1st - Todd Gnissios accepted the position of Director.

2010, August 30th - The Crossings Branch open on the westside of Lethbridge.

2012, September 13th - Elisabeth Hegerat assumed the role of Acting Director.

2013, June 1st - Tony Vanden Heuvel assumed the role of CEO.

2015, December 1 – Terra Plato assumed the role of CEO