Mr Philip Kiernan was born in Fostragh, Ballinamuck, Co Longford, Ireland on 24 January 1890.

He was the younger son of John Kiernan (b. 1840), a farmer, and Catherine Kelleher (b. 1843) who had married around 1867. 

One of ten surviving siblings born to his parents, from a total of eleven, his known siblings were: Mary (b. 3 May 1868), Anne (b. 3 June 1870), Bridget (b. 30 October 1872), Catherine (b. 18 January 1875), Bernard (b. 17 May 1880), Margaret (b. 19 August 1883),  John Joseph (b. 24 October 1885) and Ellen (b. 24 April 1894).

Philip appears on the 1901 census living with his family at house 2 in Fostragh, Ballinamuck and on the 1911 census at house 15 in Fostragh, at the time of the latter record being described as a farmer's son. Several of his siblings, including other family members, already lived in the USA. His brother John, who worked as a barman in Jersey City, New Jersey, had emigrated in 1904 but returned home to Ireland in August 1911 for an extended visit. Philip decided he would accompany him on his return to America.

Philip boarded the Titanic at Queenstown on 11 April 1912 as a third class passenger (ticket number 367229, which cost £7, 15s). It is believed he shared a cabin with his brother John and Thomas McCormack, supposedly a cousin;  he was also travelling with a large group from Co Longford, which included the Murphy sisters (Catherine and Margaret) and Kate Gilnagh.

Survivor Thomas McCormack later spoke of Philip:

"When the Titanic first struck the iceberg I was in my stateroom preparing to retire. I heard the crash as the ship struck the ice and at once hurriedly dressed and ran on deck, followed by my cousin, Philip Kieran, of Jersey City... It was brotherly love that cost 'Phil' his life. As he was hurrying toward the deck his brother John called to him to go on, that he would be there in a minute. As we reached the stairs Philip looked around, and not seeing his brother, started to return to look for him. I kept on and did not see either of them again..." 

Philip Kiernan died in the sinking and his body, if recovered, was never identified. His brother was also among the lost.