The contract covers core services such as IT security, network support, systems installation and maintenance, as well as the potential to deliver future IT projects.
It will also cover IT services that support business at constituency and regional offices.
Scottish Parliament chief executive Paul Grice said, "We were looking for proven ability to manage our existing services and also the capability to support our future technology needs.
"The new contract represents a cost saving of some 35% for the provision of the Parliament's core IT support services when compared to current arrangements."
The contract will come into effect in January 2008, and includes yearly extension clauses for five years after the initial five-year period is up, meaning it could generate up to £17.5m for LogicaCMG.
The contract replaces a previous seven-year deal with Wipro Technologies.