Cotton fiber mutants are useful tools for understanding the genetics and physiology of cotton fiber development. Currently, there are two naturally occurring, dominant lintless mutant lines, Ligon-lintless-1 (Li1) and Ligon-lintless-2 (Li2), and one man-made mutant line, Ligon-lintless-x (Lix), that exhibit extremely short lint fibers. Here we report a new lintless mutant that is the result of artificial chemical mutagenesis. In 2008, the cotton line MD 15 (PI 642769) was mutagenized with 3.2% v/v ethyl methane sulfonate (EMS). In 2010, a single Ligon-lintless-type plant was identified among the 2,000 M2 mutant progeny plants and was designated liy. This plant was crossed with the wild-type MD 15 with the objective of determining the genetic control of the lintless trait. Unlike Li1, Li2, and Lix, which are controlled by a single dominant gene, this new lintless trait is controlled by a monogenic recessive gene designated as liy. The liy plant is short and stunted and has an okra-leaf phenotype. The liy gene is not allelic to either Li1 or Li2. The genetic loci controlling these four Ligon-lintless mutations are located on four different chromosomes. This new lintless mutant will be useful in further investigating fiber elongation in cotton.