Criccieth became a borough under a charter granted by Edward I in 1284, and was the capital of Cantraf Eifionydd.
The first mayor was William de Leybourne, who was appointed constable of the castle a month after the charter was granted.
The borough was left unreformed by the Municipal Corporations Act 1835; a royal commission reported in 1876 that the corporation had long been extinct; and it was formally abolished in 1886.

The Criccieth Improvement Act 1873 had created a board of improvement commissioners to govern the town, and to take over the borough's property; and from 1889 they formed a second tier of local government below Carnarfonshire County Council.
Under the Local Government Act 1894 the improvement district became an urban district with a directly elected council, while the remainder of the civil parish was renamed Penllyn, and became part of Lleyn Rural District.
The urban district was extended between the world wars, taking in parts of Penllyn and Treflys in 1934, followed by part of Llanystumdwy in 1938.
Criccieth Urban District was abolished in 1974, and the town became part of Dwyfor District in the new county of Gwynedd, although the town retained limited powers as a community.
Dwyfor itself was abolished when Gwynedd became a unitary authority in 1996.

The town now forms an electoral division of Cyngor Gwynedd, electing one councillor; in 2008 Guto Rhys Tomos, an Independent, was elected.
Criccieth Town Council has 12 elected members; in the 2008 elections ten Independent councillors and one representing Plaid Cymru were elected unopposed.

Since 1950 Criccieth has been part of Caernarfon parliamentary constituency, and has been represented by Hywel Williams of Plaid Cymru since 2001.
In the National Assembly for Wales it has since 2007 formed part of Dwyfor Meirionnydd assembly constituency, represented by Dafydd Elis-Thomas, the Presiding Officer of the assembly, and also from Plaid Cymru; the constituency forms part of the electoral region of Mid and West Wales.
Criccieth became a borough under a charter granted by Edward I in 1284, and was the capital of Cantraf Eifionydd. The first mayor was William de Leybourne, who was appointed constable of the castle a month after the charter was granted. The borough was left unreformed by the Municipal Corporations Act 1835; a royal commission reported in 1876 that the corporation had long been extinct; and it was formally abolished in 1886.
The Criccieth Improvement Act 1873 had created a board of improvement commissioners to govern the town, and to take over the borough's property; and from 1889 they formed a second tier of local government below Carnarfonshire County Council. Under the Local Government Act 1894 the improvement district became an urban district with a directly elected council, while the remainder of the civil parish was renamed Penllyn, and became part of Lleyn Rural District. The urban district was extended between the world wars, taking in parts of Penllyn and Treflys in 1934, followed by part of Llanystumdwy in 1938. Criccieth Urban District was abolished in 1974, and the town became part of Dwyfor District in the new county of Gwynedd, although the town retained limited powers as a community. Dwyfor itself was abolished when Gwynedd became a unitary authority in 1996.
The town now forms an electoral division of Cyngor Gwynedd, electing one councillor; in 2008 Guto Rhys Tomos, an Independent, was elected. Criccieth Town Council has 12 elected members; in the 2008 elections ten Independent councillors and one representing Plaid Cymru were elected unopposed.
Since 1950 Criccieth has been part of Caernarfon parliamentary constituency, and has been represented by Hywel Williams of Plaid Cymru since 2001. In the National Assembly for Wales it has since 2007 formed part of Dwyfor Meirionnydd assembly constituency, represented by Dafydd Elis-Thomas, the Presiding Officer of the assembly, and also from Plaid Cymru; the constituency forms part of the electoral region of Mid and West Wales.
Criccieth