Andrew Graham (April 8, 1815 – November 5, 1908), born in County Fermanagh, Ireland, was an Irish astronomer/computer.
He discovered the asteroid 9 Metis in 1848 whilst employed at Markree Observatory in County Sligo.
He later worked on the Markree Catalogue, which consists of observations of about sixty thousand stars along the ecliptic taken between August 8, 1848 and 27 March 1856 and was published in four Volumes over the years 1851, 1853, 1854, 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.
He later worked as First Assistant at the Cambridge Observatory, England from 1864 to 1903 where he worked on the Cambridge Catalogue, in many ways an extension of his work at Markree but of southern zone stars, published in 1897.