Awns are stiff, hair-like structures which grow from the lemmas of wheat (Triticum aestivum L.) and other grasses that contribute to photosynthesis and play a role in seed dispersal. Variation in awn length in domesticated wheat is primarily controlled by three major genes, most commonly the dominant awn suppressor Tipped1 (B1). This study identifies a transcription repressor responsible for awn inhibition at the B1 locus. Association mapping was combined with analysis in bi-parental populations to delimit B1 to a distal region of 5AL co-localized with QTL for number of spikelets per spike, kernel weight, kernel length, and test weight. Fine-mapping located B1 to a region containing only two predicted genes, 12 including C2H2 zinc finger transcriptional repressor TraesCS5A02G542800 up-regulated in developing spikes of awnless individuals. Deletions encompassing 14 this candidate gene were present in awned mutants of an awnless wheat. Sequence polymorphisms in the B1 coding region were not observed in diverse 16 wheat germplasm while a nearby polymorphism was highly predictive of awn suppression.