Llewellyn was born in Wolverhampton on 11 September 1893, the son of James and Angelina Bird. In 1901 they were living at 30 New Street, Portobello, Wolverhampton, along with Llewellyn’s sister, Mary Jane, and brothers William, James, Bertie, Thomas, Walter, and Edward. They were living at No 1 Back, Brickkiln Street, Portobello, in 1911, and Llewellyn was working as a Stampers Help for an Oddwork Stamper.
On 10 December 1915, Llewellyn enlisted initially with the Lincolnshire Regiment (number 37078) and later served with the 42nd Labour Company (service number 24663). His address by then was 42 High Street, Portobello. He served in France until in August 1917, he was evacuated to hospital in England suffering from myalgia. It was determined that this was neither the result of, nor aggravated by, military service. On 5 November 19197 he was discharged, by which date his address was Sand Pit Valley, Noose Lane, Willenhall.
Llwellyn does not appear to have married. In 1939, he was living with his widowed mother and brother Edward in Wednesfield. He was a power presser at the stampings. Llewellyn died in Walsall in 1972.