Lewis Sydney Steward O'Malley (L.S.S. O'Malley) was a renowned ICS officer and historian of the British era, best known for preparing the District Gazetteers of undivided Bengal. The detailed repository of information he compiled at the beginning of the twentieth century, based on the history, geography, economy, and social systems of various districts in the Bengal Presidency, is still considered a primary source in South Asian research. His disciplined writing and depth of data collection played a unique role in understanding the administrative and social evolution of contemporary Bengal. Specifically, through the 'Bengal District Gazetteers' series and the book 'Indian Caste Customs', he meticulously documented the caste system and social customs of the Indian subcontinent.
