Frank Twyman FRS FInstP (17 November 1876 – 6 March 1959) was a British designer of optical instruments and co-inventor of the Twyman–Green interferometer.

[1] He attended Simon Langton School before doing an electrical engineering course at Finsbury Technical College, followed by a Siemens scholarship at Central Technical College in London.

[2] Twyman worked briefly for the Fowler Waring Cables Company testing telephone cables, before beginning work in 1898 for optical instrument manufacturing firm Adam Hilger as an assistant to Otto Hilger.

Following the death of Otto Hilger, Twyman became managing director of the firm.

[3] This included a deviation wavelength spectrometer and a spectrograph made using quartz rather than glass to enable the observation of the ultraviolet spectrum.