The Department of Posts, d/b/a India Post, is an Indian public sector postal system statutory body headquartered in New Delhi, India. It is an organisation under the Ministry of Communications. It is the most widely distributed postal system in the world and India is the country that has the largest number of post offices in the world with 164,999 post offices including 149,385 rural post offices and 15,614 urban post offices. It is involved in delivering mail (post), remitting money by money orders, accepting deposits under Small Savings Schemes, providing life insurance coverage under Postal Life Insurance (PLI) and Rural Postal Life Insurance (RPLI) and providing retail services like bill collection, sale of forms, etc.

Apart from delivering services to general public and corporates, India Post is also proud custodian of a rich heritage of postal buildings that echo the historical evolution and architectural grandeur of bygone eras. India Post has declared 44 heritage buildings so far.

Warren Hastings had taken initiative under East India Company to start the Postal Service in the country in 1766. It was initially established under the name "Company Mail". It was later modified into a service under the Crown in 1854 by Lord Dalhousie. Dalhousie introduced uniform postage rates (universal service) and helped to pass the India Post Office Act 1854 which significantly improved upon 1837 Post Office act which had introduced regular post offices in India. It created the position Director General of Post for the whole country. The DoP also acts as an agent for the Indian government in discharging other services for citizens such as old age pension payments and Mahatma Gandhi National Rural Employment Guarantee Scheme (MGNREGS) wage disbursement. With 1,64,999 post offices (as of March 2025), India Post is the widest postal network in the world.

The country has been divided into 23 postal circles, each circle headed by a Chief Postmaster General. Each circle is divided into regions, headed by a Postmaster General and comprising field units known as Divisions. These divisions are further divided into subdivisions. In addition to the 23 circles, there is a base circle to provide postal services to the Armed Forces of India headed by a Director General. One of the highest post offices in the world is in Hikkim, At 4,400m above sea level in northern India's remote Spiti Valley, the Hikkim post office is a vital connection to the outside world.

The British Raj was instituted in 1858, when the rule of the East India Company was transferred to the Crown.

A number of acts were enacted during the British Raj to expand and regulate posts and telegraphs service:

The world's first official airmail flight took place in India on 18 February 1911, a journey of 18 kilometres (11 mi) lasting 27 minutes. Henri Pequet, a French pilot, carried about 15 kilograms (33 lb) of mail (approximately 6,000 letters and cards) across the Ganges from Allahabad to Naini; included in the airmail was a letter to King George V of the United Kingdom. India Post inaugurated a floating post office in August 2011 at Dal Lake in Srinagar, Kashmir. Telegraphy and telephony made their appearance as part of the postal service before becoming separate departments. One unique telegraph office was established and operated in the capital of Lhasa until the People's Republic of China's annexation of Tibet. The Posts and Telegraphs departments merged in 1914, later separated again on 1 January 1985.

Since India became independent in 1947, the postal service continues to function on a nationwide basis, providing a variety of services. The structure of the organization has the directorate at its apex; below it are circle offices, regional offices, the superintendent's offices, head post offices, sub-post offices and branch offices. In April 1959, the Indian Postal Department adopted the motto "Service before help"; it revised its logo in September 2008.