A semiconductor package includes: a first semiconductor device including a first pad and a first metal bump structure on the first pad; and a second semiconductor device on the first semiconductor device, and including a third pad and a second metal bump structure on the third pad, wherein the first and second metal bump structures are bonded to each other to electrically connect the first and second semiconductor devices to each other. Each of the first and second metal bumps structures includes first to third metal patterns. The first to third metal patterns of the first metal bump structure are on the first pad. The first to third metal patterns of the second metal bump structure are on the third pad. The first and third metal patterns include a first metal having a first coefficient of thermal expansion less than that of a second metal of the second metal pattern.