Freezing tolerance and genomic data for red clover accessions used for a genome-wide association study (GWAS) to identify loci associated with freezing tolerance in the EUCLEC collection of mostly European red clover accessions. Freezing tolerance was measured as LT50. The genomic data are allele frequencies of single nucleotide polymorphisms (SNPs) and short read-backed haplotypes called in genotype by sequencing-data on pools of DNA (pool-GBS); one pool of 200 individuals per accession. The data were used to generate genomic relationship matrices. SNP data were used to calculate linkage disequilibrium.