Who was the Viceroy of India when the Rowlatt Act was passed?

The Rowlatt Act was passed in 1919 during the period when Lord Chelmsford was serving as Viceroy of India. The Montagu–Chelmsford reforms and the Government of India Act, 1919 (often associated with Montagu and Lord Chelmsford) place Chelmsford at the centre of Indian administration in this period, indicating his viceroyalty during the enactment of major 1919 measures [1]. Historical summaries of the Montagu–Chelmsford period record that Lord Chelmsford served as Viceroy from 1916 to 1921, which covers 1919 when the Rowlatt Act was passed; thus Lord Chelmsford was the Viceroy at that time [2].

Sources

1. [1] Laxmikanth, M. Indian Polity. 7th ed., McGraw Hill. > Chapter 1: Historical Background > Government of India Act of 1919 > p. 6
2. [2] https://en.wikipedia.org/wiki/Montagu%E2%80%93Chelmsford_Reforms