"On Ilkla Moor Baht 'at" (Standard English: On Ilkley Moor without a hat) is a folk song from Yorkshire, England. It is sung in the Yorkshire dialect, and is considered the unofficial anthem of Yorkshire. According to Andrew Gant, the words were composed by members of Halifax Church Choir "some 50 years after Clark wrote his melody", on an outing to Ilkley Moor near Ilkley, West Yorkshire. It is classified as numbers 2143 and 19808 in the Roud Folk Song Index.