Ralph Agas (or Radulph Agas) (c. 1540 – 26 November 1621) was an English land surveyor and cartographer. He was born at Stoke-by-Nayland, Suffolk, in about 1540, and lived there throughout his life, although he travelled regularly to London. He began to practise as a surveyor in about 1566, and has been described as "one of the leaders of the emerging body of skilled land surveyors".

Agas is particularly known for his large-scale town map of Oxford (surveyed 1578, published 1588). Early maps of London and Cambridge were also formerly attributed to him, but these attributions are no longer upheld.
What did Ralph Agas did as a profession?
Ralph Agas was an English land surveyor and cartographer, he was born at Stoke-by-Nayland, Suffolk.