Sir Richard Udny (1847–1923) was an official in British India, best known for his role in defining the border with the Emirate of Afghanistan. He took part in the border survey for the stretch between the Hindu Kush range in the north-east to Landi Kotal. This demarcation was the first stage in making the Durand Line of 1893 concrete in geographical terms, a process that lasted into the 20th century.