Andrew Graham (8 April 1815 – 5 November 1908) was an Irish astronomer, orbit computer and discoverer of the asteroid 9 Metis.

[3] The observatory had been established in 1830 by Colonel Edward Joshua Cooper (1798–1863) as a private institution on his country estate.

[7] Graham discovered the asteroid 9 Metis from Markree on 25 April 1848 while observing with a 3-inch aperture wide-field telescope manufactured for comet searching by the German instrument maker Ertel.

[3] Graham later worked on the Markree Catalogue, which consisted of observations of about sixty thousand stars along the ecliptic taken between 8 August 1848 and 27 March 1856, and was published in four volumes in the years 1851, 1853, 1854 and 1856 respectively.

Whilst working on this, he developed the square-bar micrometer, which greatly increased the efficiency of determining positions (right ascension and declination) of celestial objects.