Dataset contains microsatellite genotypes specific for Macrocystis pyrifera (giant kelp). Table 1 describes seven loci from blades collected from 62 sites from Alaska, USA, to Baja California, Mexico, and Table 2 blades collected at 38 sites (subpopulations) in central California (Monterey Bay). Each row is the multilocus genotype for a single specimen (individual). These data were described in Johansson ML, Alberto F, Reed DC, Raimondi PT, Coelho NC, Young MA, Drake PT, Edwards CA, Cavanaugh K, Assis J, Ladah LB, Bell TW, Coyer JA, Siegel DA, Serrão EA (2015) Seascape drivers of Macrocystis pyrifera population genetic structure in the northeast Pacific. Molecular Ecology. 24, 4866–4885.