Population
The town's resident population according to the 2001 Census was 11,237. The resident population of Holy Island as a whole was 13,579. Holyhead's population has fallen marginally in recent decades due to various factors, including limited housebuilding, smaller household sizes, demographic changes and local economic circumstances.
The population in surrounding areas such as Trearddur Bay has been increasing.
History
The origins of the town date back to the building of a Roman Naval Base around 300AD, and the establishment of a religious centre within its walls in about 540AD. A small town gradually developed around this site during the centuries which followed. Holyhead developed into a significant town mainly because of its role as a port linking Ireland and Britain, and the Admiralty decision to create a major sheltered harbour of refuge for sailing ships by building the breakwater. It also became an important centre for railways. Hotels and shops developed from this and Holyhead became the main service town for much of Anglesey. The town has also developed as an industrial centre, including boat building and repairs. A number of factories were located in Holyhead during the 20th century, the largest being the aluminium smelter.

Employment
Major employers in Holyhead include the Port/Stena, Anglesey Aluminium, Eaton, Holyhead Boatyard, Schools, Holyhead Town Centre, Tesco, Morrisons and the Retail Park. The Hedsrom factory closed recently with the loss of about 60 jobs. Conversely, about 60 jobs were recently gained as part of a new Stena Call-Centre. The Retail Park has created many part-time jobs, with about 250 jobs being created at the new Morrisions store. There were major job losses in 2009 due to the ending of smelting at Anglesey Aluminium (c450 jobs lost) and manufacturing at Eaton Electrical (c220 jobs lost).
Environment
Holyhead is a port town, located in attractive rural/coastal surroundings. Much of Holy Island is designated as an Area of Outstanding Natural Beauty and includes significant areas of Heritage Coast. Heritage Conservation Areas have been designated for Holyhead Town Centre, Newry Beach, and Holyhead Mountain Village. The area includes a significant number of listed buildings, ancient monuments and tree preservation orders. A new waste water treatment works has been built to improve local sea water quality.
Communications
The A55 North Wales expressway was extended across Anglesey in 2001, and provides good road access. Holyhead also benefits from rail access to Chester and ferry links to Dublin and Dun Laoghaire. There are proposals to create a small civilian airport at nearby RAF Valley. Broadband IT communication links are available in Holyhead.