The Indian Slavery Act, 1843, also Act V of 1843, was an act passed in British India under East India Company rule, which outlawed many economic transactions associated with slavery.

The sale of any person as a slave was banned, and anyone buying or selling slaves would be booked under the Indian Penal Code, with offence carrying strict punishment.

Some East India Company officials opposed the act, citing Hindu and Muslim customs, who maintained the act would be seen as interference in traditional structures. Evangelical politicians who had led successful abolish slavery campaigns in West Indies prevailed and the Act was implemented.

Historians are divided on whether the Act was able to exclude caste and slavery. The condition of workers in tea plantations in Tamil Nadu and Assam was compared to that of African, West Indian counterparts who worked in sugar plantations. Lack of alternatives meant tea plantation workers had become indentured labourers despite the Act,which historian Amalendu Guha maintained was a new form of slavery.