Ongoing climate change and increase in extreme events are significantly impacting marine coastal ecosystems, including temperate kelp forests. Kelp’s adaptive potential and response to climate change partly relies on genetic diversity and composition which can vary among populations. Using genetic tools to identify populations likely to tolerate future environmental conditions is critical for effectively planning conservation initiatives. Using >9,000 single nucleotide polymorphisms (SNPs), we characterised the genomic patterns of diversity and structure for the kelp Ecklonia radiata along the eastern coastline of Australia, a major global warming hot-spot. We found a relatively weak population structure in coastal populations within the main path of the East Australian Current when compared to stronger patterns of genetic isolation towards higher latitudes, supported by a large amount of private alleles in Tasmanian populations. The spatial distribution of genetic diversity showed minimum values at the northern rear edge site as well as in Tasmania. Outlier identification and gradient forest analysis are being conducted to further understand processes of local adaptation, including estimation of genomic vulnerability via a mismatch between current and future predicted genotype–environment relationships. Ultimately, those results will inform proactive management strategies to preserve kelp forests and their associated ecological and economic services.