George was a musical instrument maker in the family business. According to census information, George was born in the St. Martin-in-the-Fields registration district (now incorporated into the City of Westminster), although it's not known exactly where. The Butlers' London shops as listed below would eventually be located in this area.
William Waterhouse's "The New Langwill Index: A Dictionary of Musical Wind-Instrument Makers and Inventors" gives the following dates and addresses for the Butler business (my notes are in parentheses):
1859: 17 Brydges St., Covent Garden, London
1860-1865: 57 Greek St., London
1865-1898: 29 Haymarket, London (now the address of the 'Tiger Tiger' club)
1898-1913: 29 Haymarket (under the name 'George Butler & Sons')
1868-1882: 11 Ellis Quay, Dublin
1882-1926: 34 Bachelor's Walk, Dublin (in Monument House)
1926-1927: 2 Lower Abbey St., Dublin
[Notes on the above dates: (i) According to the 1871 census of England, George was employing at that time five men and four boys (in the Haymarket premises), and (ii) The business actually moved from Bachelor's Walk to Lower Abbey St. in 1917 although the family seems to have retained the Bachelor's Walk premises]
George and his wife, Jane, seem to have moved around a lot after their marriage: in 1863 they were living at 29a Haymarket (next door to their future shop?); their daughter Mary was born in the Richmond area in 1865, suggesting they were living there at the time; in 1871, according to the census of that year, their home was 6 Brompton Square, Kensington; by the time of the 1881 census, they were living at 32 St. Mary Abbot's Terrace, Kensington; in 1891, the census shows they were living at 9 Gunterstone Road in West Kensington; and by the time of the 1901 census, they had moved to 23 Rowan Road in nearby Hammersmith.
Interestingly, at the time of the 1891 census, the family of Thomas Hussey, whose sons married George's daughters, Mary and Jane, lived at 23 St. Mary Abbot's Terrace (having moved there between 1884 and 1991), the same street where George and Jane were living in 1881. Perhaps the two families had been close neighbours at some point and perhaps that's how Mary and Jane first met the Hussey boys. Another possibility is that the Butlers and the Husseys met through their connection with St. Edmund's College in Hertfordshire: Mary's and Jane's younger brother, William, may have attended the college at the same time as some of Thomas Hussey senior's sons.
George died in 1911 at the home of his son Thomas at 59 Rowan Road in Hammersmith. The cause of death was "cerebral haemorrhage, 4 months; hemiplegia; congestion of lungs".