To provide a yarn splicing device capable of accurately guiding an upper yarn and a lower yarn to an untwisting work position, and to provide a yarn winding device having the same.

A disk splicer 30 includes: disk members 33 and 33 for untwisting a lower yarn YA and an upper yarn YB to be spliced by twisting; a guide member for guiding the lower yarn YA and the upper yarn YB to untwisting work positions YAW and YBW of the disk members 33 and 33; a yarn handling lever for leading the lower yarn YA and the upper yarn YB to the guide member. The guide member is formed with: a lower yarn guide 42A for guiding the lower yarn YA to the untwisting work position YAW; and an upper yarn guide 42B for guiding the upper yarn YB to the untwisting work position YBW. The yarn handling lever is formed with: a lower yarn positioning part 32A for leading the lower yarn YA to the lower yarn guide 42A; and an upper yarn positioning part 32B for leading the upper yarn YB to the upper yarn guide 42B.