Sir Marc Isambard Brunel was a French-British engineer who is most famous for the work he did in Britain. He constructed the Thames Tunnel and was the father of Isambard Kingdom Brunel.

The Thames Tunnel is a tunnel beneath the River Thames in London, connecting Rotherhithe and Wapping. It measures 35 ft (11 m) wide by 20 ft (6.1 m) high and is 1,300 ft (400 m) long, running at a depth of 75 ft (23 m) below the river surface measured at high tide. It is the first tunnel known to have been constructed successfully underneath a navigable river. It was built between 1825 and 1843 by Marc Brunel, and his son, Isambard, using the tunnelling shield newly invented by the elder Brunel and Thomas Cochrane.