Kidney stone disease is a common condition. To search for sequence variants conferring risk of kidney stones, we conducted a genome-wide association study in 3,773 cases and 42,510 controls from Iceland and The Netherlands. We discovered common, synonymous variants in the CLDN14 gene that associate with kidney stones (OR = 1.25 and P = 4.0 × 10−12 for rs219780C). Approximately 62% of the general population is homozygous for rs219780C and is estimated to have 1.64 times greater risk of developing the disease compared to noncarriers. The CLDN14 gene is expressed in the kidney and regulates paracellular permeability at epithelial tight junctions. The same variants were also found to associate with reduced bone mineral density at the hip (P = 0.00039) and spine (P = 0.0077).