Now online for free, an authoritative reference work of nearly 11,000 lives for scholars of Irish history, society and culture.
Although it’s unlikely you’ll find your relative there will almost certainly be somebody from a place of interest to be found using the full-text advanced search.
Check out locations in your family history. Bunclody where I stayed for a vacation has seven mentions, Kilkeel where I may have ancestry has 13. Look further afield too. There are 44 entries mentioning Ottawa.