Walter Ennis was born in Sheffield, Yorkshire, England on 3 April 1878, at 170 Greystock Street, Brightside Bierlow, Sheffield.  He was baptised on 28 April that year in All Saints Church, Brightside, Sheffield.  

He was the son of James Ennis (b. 1842), a slater and native of Swinton, Yorkshire, and Ellen Hallowell (b. 1848) who hailed from Seghill, Northumberland and they had married in around 1870, going on to produce nine children, three of whom were lost in infancy. Their other known children, besides Walter, were: Mary C. (b. 1871), John Robert (b. 1872), Annie (b. 1874), George Hallowell (b. 1876), Albert (b. 1880), Minnie (b. 1884) and Julia Ellen (b. 1887).

Walter's parents initially settled in Blyth, Northumberland and only moved to Sheffield prior to his birth in 1878. They show up on the 1881 census living at House 2, Court 2, Saville Street in Brightside Bierlow, Sheffield and would have moved to House 3, Court 7, Prawber Street in Brightside by the time of the 1891 census.

Walter was married in Ecclesall Bierlow in 1898 to Mary Ann Rose (b. 1879 in Sheffield) and they settled in their native Sheffield, going on to produce four daughters: Annie (b. 1899), Doris Mabel (b. 1901), Christine (b. 1903) and Violet (b. 1906).

Walter, his wife and first child appear on the 1901 census living at 32 St Michael Road, Sheffield and he is described as a shampooer and Turkish bath attendant. The family moved to Southport, Lancashire sometime after the birth of their youngest child and appear on the 1911 census living at 141 Bedford Road, Birkdale, Southport. Walter described himself as a masseuse but, curiously, gave his birthplace as Blyth, Northumberland.

When he signed-on to the Titanic, on 6 April 1912, Walter gave his address as 141 Bedford Road, (Birkdale), Southport. As a Turkish bath attendant he received monthly wages of £6. The Titanic was his first ship, having previously worked in a similar position at Smedley Hydro in Birkdale. Contemporary newspapers reported that Walter was a very strong swimmer.

Ennis died in the sinking. His body, if recovered, was never identified.

His widow Mary never remarried and remained in Southport where she died in 1962.

His daughter Annie (later Mrs Charles Sullivan) died in Lancashire in 1981. Doris Ennis (later Mrs John Oldfield) died in 1997 in Macclesfield, Cheshire. Christine Ennis was never married and she remained in Southport and died in 1978. What became of his daughter Violet is unclear.

Walter Ennis, is remembered on his wife's headstone in Liverpool Road Cemetery, Birkdale, Sefton, Merseyside, England (Section R, Row 13).