Sir Thomas Bouch (; 25 February 1822 – 30 October 1880) was a British railway engineer.
He was born in Thursby, near Carlisle, Cumberland, and lived in Edinburgh.
As manager of the Edinburgh and Northern Railway he introduced the first roll-on/roll-off train ferry service in the world.
Subsequently as a consulting engineer, he helped develop the caisson and popularised the use of lattice girders in railway bridges.
He was knighted after the successful completion of the first Tay Railway Bridge, but his reputation was destroyed by the subsequent Tay Bridge Disaster, in which 75 people are believed to have died as a result of defects in design, construction and maintenance, for all of which Bouch was held responsible.