Arhopala halmaheira is a butterfly in the family Lycaenidae. It was discovered by George Thomas Bethune-Baker in 1904. It is found in Halmahera. This species is monotypic.
The male is shining light blue above, with the black border 1 to 2.5 millimeters. The female, which is lighter blue, has a black border of 7 millimeters. Both sexes are dark brown below with a slight tinge of purple, with the darker markings white-edged.