Provided are leather fibers for yarn. The leather fibers forming the yarn are obtained from cowhide. An amount of the leather fibers having an H value of 30 or more is 30% by weight or more of a total leather fibers contained in the yarn. The H value is defined by the following Equation 2: [Equation 2] H=L/D where L: leather fiber length, and D: leather fiber thickness. A thickness index (M) of the leather fibers satisfies Equation 1: [Equation 1] M=D1/D2≤60 where D1: an average thickness of 0 fibers having a highest thickness in 1 mg of leather fibers, and D2: an average thickness of 10 fibers having a lowest thickness in 1 mg of leather fibers.