The 1921 Buckingham and Carnatic Mills strike was a strike by the workers of Buckingham and Carnatic Mills in the city of Madras (now called Chennai), India, against the managing company, Binny and Co. The strike, which lasted from June to October 1921, caused severe losses to the Madras economy. It also created a rift in the ruling Justice Party forcing many Dalit leaders to leave.
The Madras Labour Union was one of the first organised labour unions in India and was founded by B. P. Wadia and V. Kalyanasundaram Mudaliar on 3 April 1918. Early union activity took place in the Buckingham and Carnatic Mills during October–December 1920 when workers struck work in protest against working conditions. The government responded by ordering the police to shoot down striking workers on 9 December 1920 bring the strike to a forceful end.
There was widespread unrest among the workers over the low wages and poor working conditions. Their demands were supported by Indian nationalists C. Rajagopalachari, S. Kasturi Ranga Iyengar, A. Rangaswami Iyengar, Singaravelu Chetty, V. Chakkarai Chettiar and S. Satyamurti and by the self-rule supporting Indian National Congress as well as the pro-British Justice Party.
On 20 May 1921, the workers in the Spinning Department of the Buckingham and Carnatic Mills refused to work until the management agreed to discuss their wage rise demands. The protest reached serious proportions when an official strike was declared on 20 June. The striking workers were led by Congressman V. Kalyanasundaram Mudaliar. The Indian National Congress convened a meeting in Madras on 10 July 1921; in this meeting, C. Rajagopalachari moved for a resolution sympathizing with the workers of the Buckingham and Carnatic Mills and supporting their cause.