A full microfilm copy of the 1901 Irish Census is available at the LDS Family History Library in Salt Lake City. You may order a copy at your local LDS Research Centre.
A partial census is available on line at
The areas it covers in County Down are Loughinislannd, Drumgooland, Kilmegan amd Magherahamlet(partial)
Other Counties are Galway, Leitrim, Sligo, Mayo, Roscommon, Westmeath, wexford.