Haplogroup A-L1085, also known as haplogroup A0-T is a human Y-DNA haplogroup. It is part of the paternal lineage of almost all humans alive today. The SNP L1085 has played two roles in population genetics: firstly, most Y-DNA haplogroups have diverged from it and; secondly, it defines the undiverged basal clade A-L1085*. A0-T has two primary branches: A-V148 (also known as haplogroup A0) and haplogroup A-P305 (haplogroup A1).