John Grenham came to Irish professional genealogy in 1981, as one of the panel of Irish Genealogical Office researchers and later worked for Hibernian Research. As in-house researcher for the Genealogical Office in 1990-91, he was instrumental in setting up the GO Consultation Service, the forerunner of the current Advisory Services in the National Library of Ireland and National Archives of Ireland.
He was Project Manager with the Irish Genealogical Project from 1991 to 1995 and later went on to develop and market his own genealogical software, 'Grenham's Irish Recordfinder'. He ran the Irish Times/Irish Ancestors website from 1998 to 2016. It now runs on his own site. In 2005, he was the first Genealogist-in-Residence at Dublin City Library and Archive. He is responsible for developing most of the heritage databases on databases.dublincity.ie.
He was awarded a fellowship of The Irish Genealogical Research Society in 2007 and of the Genealogical Society of Ireland in 2010. Among his publications are the standard guide to Irish genealogy, Tracing your Irish Ancestors (4th ed.2012), Clans and Families of Ireland (1995), Generations (1996), "The Genealogical Office and its Records" in The Genealogical Office (1999), Grenham's Irish Surnames (CD-ROM, 2003), The Atlantic Coast of Ireland (2014) and numerous articles and columns in the UK magazine Your Family Tree. He wrote the "Irish Roots" column and blog in The Irish Times between 2009 and 2016. The blog is now at www.johngrenham.com/blog. In 2011 and 2014, he was co-presenter of the Irish television show "The Genealogy Roadshow". In 2014, 2015 and 2016, he delivered a ten-week diploma in family history course at City Colleges in Dublin.
His website is www.johngrenham.com.