Frederick Dornhorst, KC was a Ceylonese (Sri Lankan) lawyer. A King's Advocate, he was a leader of the bar.
Educated at the prestigious Colombo Academy (now Royal College Colombo), Dornhorst became a teacher at the Colombo Academy before moving on to a legal career and became highly respected lawyer after becoming a Barrister at the Inner Temple. In 1903 he was sworn in as a King's Counsel with Ponnambalam Ramanathan and Thomas De Sampayo, the first "silks" of the Bar of Ceylon.
The Dornhorst Memorial Prize is the most coveted award at Royal College Colombo, awarded to annually to the most popular student each year in the memory of Frederick Dornhorst.