Maryborough West or West Maryborough[1] (Irish: Port Laoise Thiar[2]) is a barony in County Laois (formerly called Queen's County or County Leix), Ireland.

[citation needed] Maryborough West is located in west-central County Laois, with the River Nore flowing through its southern part.

[5] Maryborough East and West were in the Middle Ages the land of the Cinel Crimthann, an Irish clan with the surname Ó Duibh (Duffy or O'Diff).

[6] Maryborough was originally a single barony; it was divided into East and West before 1807.

Below is a list of settlements in Maryborough West barony: