Hyginus, usually distinguished as Hyginus Gromaticus, was a Latin writer on land-surveying, who flourished in the reign of Trajan (AD 98–117). Fragments of a work on boundaries attributed to him are found in Corpus Agrimensorum Romanorum, a collection of works on land surveying compiled in Late Antiquity.
The cognomen means "agrimensor" or "surveyor" and derives from , one of their common tools in antiquity. Its application to Hyginus derives from the , whose copy of the reads in part [] ("The establishment of Kyginus the Surveyor explains well..."). Other manuscripts of the text like the Palatinus Vatic. Lat. 1564 have instead ("The book of Hyginus on surveying explains..."), in which the adjective is grammatically attached to the book rather than the author. For this reason, some scholars like Brian Campbell avoid the epithet and instead call him simply Hyginus or Hyginus 1 (to distinguish him from another Hyginus whose work appears in the same text).
Hyginus was probably active around the year 100.
His only extant work is [] ("On the Establishment [of Boundaries]") in the ("Body of Roman Surveying"), a collection compiled in Late Antiquity. is preserved only in a corrupt text, but its contents include important evidence on the Latin reception of Greek astronomical and mathematical texts. Notably, in his discussion of the establishment of the and the main eastwest and northsouth thoroughfares in most Roman townsHyginus is decidedly in favour of the construction of the using a gnomon (sundial) and compares this method with other less precise methods such as using the location of sunrise and sunset. The text has some connection with a passage included in Bubnov's ("Geometric Works of Unknown Authors"). Editions of the work appear in C. F. Lachmann's , Vol. I (1848), Carl Olof Thulin's , Vol. I (1913), and Brian Campbell's Writings of the Roman Land Surveyors (2000).
Another work by Hyginus, ("Surveying Book on the Division of Fields") is transmitted only as a title and might be the same as .
A treatise on Roman military camps () was formerly attributed to this Hyginus, but it was probably composed later, around the 3rd century and is thus now attributed to "Pseudo-Hyginus".