Mr Joseph John Beattie was born at 9 Gay Street in Belfast, Ireland (modern-day Northern Ireland) on 1 October 1871. 

Hailing from a Presbyterian family he was the son of Robert Welsh Beattie¹, a carpenter, and Mary Jane De Ermond and had at least one sibling, his sister Mary Eliza (b. 1 September 1877). 

He was married on 16 September 1891 in St Anne's Church, Belfast to linen spinner Maria Welsh; both were residents of Abbot Street, Belfast at the time and he was described as a labourer. Maria was born in Templemore, Ballymacarrett in east Belfast on 14 September 1867 to labourer Davidson Welsh and the former Mary Jane Patterson. 

Joseph and Maria would have four children: Maria (b. 3 July 1898), Margaret (b. 23 February 1900), Agnes (b. 24 May 1903) and Joseph (b. 19 December 1906). 

Joseph appears with his family on the 1901 census living at 23 Canton Street in the Ormeau district of south Belfast and he was described as a ship's fireman. Whilst absent from the 1911 census and likely at sea, his wife and children were listed as living at 3 Isthmus Street, Belfast, again in the Ormeau district where they had lived for at least the last five years.

Beattie had previously worked on the Olympic; when he first signed-on to the Titanic on 29 March 1912 for the delivery trip he left a cross (x) and his name was signed for him, suggesting that he was illiterate. The register states that he was due aboard at 4 am on 1 April for the sea trials but because of bad weather the trials did not take place until 2 April. When he re-signed on 6 April 1912, he appears to have signed his own name and gave the Sailors' Home, Southampton as his local address. As a greaser he received monthly wages of £6, 10s.

Joseph Beattie died in the sinking and his body, if recovered, was never identified.

Leaving a widow and four children, his daughter Margaret was reportedly in frail health and the lack of income for the family only pushed them closer to poverty. Margaret succumbed to pulmonary tuberculosis on 24 October 1912 aged just twelve years.

Maria Beattie later sued Messrs Ismay, Imrie & Co. Ltd and was awarded £294, 15s; one-third of that sum was apportioned to Mrs Beattie whilst the remainder was distributed among her children. 

On the first anniversary of the sinking Maria Beattie placed the following poem in the Belfast Telegraph:

I often sit and think of him
When I am all alone,
For memory is the only friend
That grief can call its own.
Like ivy on the withered oak
when other things decay,
My love for him will still keep green
and never fade away.

Beattie is commemorated on the Titanic Memorial in the grounds of Belfast City Hall. 

His widow Maria remained on Isthmus Street, later house 7, for the rest of her life and died following a stroke on 3 April 1945.  

His eldest daughter Maria was married in St Anne's Cathedral, Belfast on 16 May 1928 to labourer Samuel Porter. What became of her thereafter is unclear. The fate of her surviving siblings also remains uncertain.