It was built by the Mughal emperor Shah Jahan (Shāh Jahān) (reigned 1628–58) to immortalize his favourite wife, Mumtaz Mahal (“Chosen One of the Palace”). She died in childbirth in 1631, after having been the emperor's inseparable companion since their marriage in 1612. The name Taj Mahal is a corruption of her title. The plans for the complex have been attributed to various architects of the period, although the chief architect was probably Ustad Ahmad Lahawri, an Indian of Persian descent. The five principal elements of the complex—main gateway, garden, mosque, jawab (literally “answer”; a building mirroring the mosque), and mausoleum (including its four minarets)—were conceived and designed as a unified entity according to the tenets of Mughal building practice, which allowed no subsequent addition or alteration. Building commenced about 1632. More than 20,000 workers were employed from India, Persia, the Ottoman Empire, and Europe to complete the mausoleum itself by about 1638–39; the adjunct buildings were finished by 1643, and decoration work continued until at least 1647. Construction of the 42-acre (17-hectare) complex spanned 22 years at a cost between four and five million rupees.

Flanking the mausoleum near the northwestern and northeastern edges of the garden, respectively, are two symmetrically identical buildings—the mosque, which faces east, and its jawab, which faces west and provides aesthetic balance. Built of red Sikri sandstone with marble-necked domes and architraves (architrave), they contrast in both colour and texture with the mausoleum's white marble.

The garden is set out along classical Mughal lines—a square quartered by long watercourses (pools)—with walking paths, fountains, and ornamental trees. Enclosed by the walls and structures of the complex, it provides a striking approach to the mausoleum, which can be seen reflected in the garden's central pools.

A tradition relates that Shah Jahan had originally intended to build another mausoleum across the river to house his own remains, the two structures to be connected by a bridge. He was deposed by his son Aurangzeb, however, and imprisoned for the rest of his life in Agra Fort, on the right bank of the Yamuna River 1 mile (1.6 km) west of the Taj Mahal.

Over the centuries the Taj Mahal has been subject to neglect and decay. A major restoration was carried out at the beginning of the 20th century under the direction of Lord Curzon (Curzon, George Nathaniel Curzon, Marquess, Viscount Scarsdale, Baron Ravensdale), then the British viceroy of India. More recently, air pollution caused by emissions from foundries and other nearby factories and exhaust from motor vehicles has damaged the mausoleum, notably its marble facade. A number of steps have been taken to reduce the threat to the monument, among them the closing of some foundries and the installation of pollution-control equipment at others, the creation of a parkland buffer zone around the complex, and the banning of nearby vehicular traffic. A restoration and research program for the Taj Mahal was initiated in 1998. Progress in improving environmental conditions around the monument, however, has been slow.

The Taj Mahal has come increasingly to be seen as an Indian cultural symbol. Some Hindu nationalist groups have attempted to diminish the importance of the Muslim influence in accounting for the origins and design of the Taj Mahal.