[citation needed] Maryborough East is located in central County Laois.

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] It is referred to in the topographical poem Tuilleadh feasa ar Éirinn óigh (Giolla na Naomh Ó hUidhrín, d. 1420): Fa Dún Mascc as mín fuinn, O'Duib for Chenel cCrioṁṫainn, Triath an tíre fa ṫoraḋ, Iath as míne measrogaḋ.

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

Below is a list of settlements in Maryborough East barony: