Originally used as offices by Imperial Chemical Industries (ICI), it has served as the headquarters of the United Kingdom's internal Security Service (commonly known as MI5) since December 1994.

The building was constructed in 1929–30 by John Mowlem & Co on riverside land cleared after the disastrous 1928 Thames flood severely damaged run-down residential properties.

At the same time, Thames House, which was largely used as government offices by then, became vacant when the Department of Energy left the southern half in 1989 and it was decided to convert and refit much of it for MI5's use.

The GMW Partnership undertook the design and Mowlem carried out the necessary reconstruction work from 1990, which included part-infilling of the building's distinctive archway.

[8] On 1 June 2007, the building (other than the steps that give access to it) was designated as a protected site for the purposes of Section 128 of the Serious Organised Crime and Police Act 2005.