Thomas Bonnar (d. 1847) was a Scottish interior designer and architect of note, working in the Edinburgh area. He is particularly remembered for his outstanding ceilings.
Thomas was the father of the artist William Bonnar (1800–1853) and the engraver Thomas Bonnar (1810–1873), who collaborated with each other on several works.
The group are also known by the family company name of Bonnar & Co.