We developed a panel of single nucleotide polymorphism (SNP) markers for 159 thornback ray Raja clavata sampled in the Bay of Biscay during the period 2011-2016 using a RADSeq protocol. Demultiplexed sequences were aligned to the genome of Leucoraja erinacea which was used as reference genome. From an initial set of 389 483 putative SNPs, we only retained loci with a calling frequency percentage above 50%, MAF (minor allele frequency) above 0.01 and read depth below 500 to remove spurious SNPs. This resulted in selecting 43 088 SNPs. The genotype data is provided in variant call format (vcf ). Note that contigs contain several SNPs.