1911 census of Ireland

The 1911 census of Ireland was the last census that covered the whole island of Ireland. Censuses were taken at ten-year intervals from 1821 onwards, but the 1921 census was cancelled due to the Irish War of Independence.

The original records of the 1821 to 1851 censuses were destroyed by fire at the Four Courts in Dublin during the Irish Civil War, while those between 1861 and 1891 were possibly pulped during the First World War. All that remained were the 1901 and 1911 census, with the latter put online in 2009 by the National Archives of Ireland.

Information collected
The census information was recorded on the following forms:
 * Form A, which was completed by the head of the family
 * Forms B1, B2, and N, which were completed by the census enumerator

Head of the family
Form A, which was completed by the head of the family, contained the following information for each person in the home on the night of 2 April: The form was signed by both the census enumerator and the head of the family.
 * Name and Surname
 * Relation to Head of Family
 * Religious Profession (Protestants were requested to indicate denomination)
 * Education (whether able to read and write)
 * Age (last birthday) and Sex
 * Rank, Profession, or Occupation
 * Particulars as to Marriage (marital status, length of marriage, number of children born alive, number of children still living)
 * Where Born
 * Irish Language (whether able to speak Irish)
 * Disability: if persons were:
 * Deaf and Dumb
 * Dumb only
 * Blind
 * Imbecile or Idiot (i.e. intellectually disabled)
 * Lunatic (i.e. severely mentally ill)

Census enumerator
Form B1, which was known as the House and Building Return, was completed by the enumerator and summarised the following administrative information for the street or townland, or part thereof: It then summarised the following information pertaining to the houses and families of the street or townland. The information about houses included: The information about families included:
 * County
 * Parliamentary Division
 * Poor Law Union
 * District electoral division
 * Townland
 * Parliamentary borough
 * City
 * Urban District
 * Town or Village
 * Street
 * Barony
 * Parish
 * Number of House or Building
 * Whether Built or Building
 * Whether Private Dwelling, Public Building, School, Manufactory, Hotel, Public-house, Lodging-house, Shop, etc.
 * Number of Out-Offices and Farm-steadings as returned on Form B2
 * Whether House Inhabited
 * Walls (whether made of permanent or perishable material)
 * Roof (whether made of permanent or perishable material)
 * Rooms (number, whether 1, 2–4, 5–6, 7–9, 10–12, 13+)
 * Windows in Front (exact number)
 * Class of House (1st, 2nd, 3rd, or 4th, based on information supplied above)
 * Number of distinct Families in each House
 * Name of the Head of each Family residing in the House
 * Number of Rooms occupied by each Family
 * Total Number of Persons in each Family
 * Date on which Form A was collected
 * Number of Persons in each Family who were sick on 2 April 1911
 * Name of the Landholder (if any) on whose Holding the House is situated
 * Number on Form M1 if House is on the Holding of a Landholder

Form B2, the Return of Outhouses and Farm-Steadings, gave more detailed information on secondary buildings attached to a property, such as outhouses, workshops, and various kinds of farm buildings.

Form N, the Enumerator's Abstract for a Townland or Street, recorded the enumerator's name, the same administrative information as listed for Form B1, the properties and which were inhabited, and the numbers of families, males, and females, and persons of each religious denomination.

Total
The total population of Ireland according to the 1911 census was 4,390,219 of whom 2,192,048 were male and 2,198,171 were female.

By county
*Note: ''The County Borough of Belfast, established in 1888, straddled the border between Down and Antrim. The River Lagan was the traditional boundary of the two counties. The borough of Belfast had 15 wards, three of which - Ormeau, Pottinger and Victoria - were south of the Lagan and have been included as part of County Down's population. The remainder have been added to County Antrim's population.''

Religion
According to the 1911 census, religious profession broke down as follows:

Viewing the returns
The census returns of 1911 for all 32 counties are available online. The website is freely accessible, with no charge for viewing any of the material.

The original manuscripts of the Census of Ireland are all housed in the National Archives of Ireland. The returns are arranged by townland for rural areas and by street in cities, and it is necessary to know the townland or street where a person lived and its corresponding district electoral division to find the record of a particular person of interest.

The Family History Library also holds microfilm copies of the original 1911 census returns and these can be viewed at the Library in Salt Lake City, Utah. A list of Royal Irish Constabulary police barracks, for which the Form H Barrack Returns can be identified, is available at the free to use Royal Irish Constabulary Research Forum.