He was born at Brodie House, Bambalapitya and educated at S. Thomas' College, Prince of Wales' College and Royal College and completed his education at Highbury House School[1] St Leonards-on-Sea, where he excelled as a sprinter and pursued a degree in music at Trinity Hall, Cambridge.
[5] He was appointed to the 'Salaries Commission of 1912' and paid workers from his private funds when the government refused to pay wages for the week-long railway strike.
[6] De Soysa was a proprietor of the Ceylon Morning Leader newspaper.
[7] On 4 February 1892 he married Mary Margaret de Silva of Henley House (now St. Bridget's Convent, Colombo).
[2][8] In 1895 he built the Chevaliar Jusey de Silva ward at the Lady Ridgeway Hospital for Children and in 1913 inaugurated the Ceylon School for the Deaf and Blind, Ratmalana.