Catalyzes the transfer of a phosphate from ATP to alpha-D- galactose and participates in the first committed step in the catabolism of galactose. {ECO:0000269|PubMed:12694189, ECO:0000269|PubMed:7542884}. This is the function of GALK1 (galactokinase 1, ENSG00000108479).