Semiconductor devices may include standard cells arranged in a first direction and a second direction intersecting the first direction. Both the first and second directions may be parallel to an upper surface of the substrate. Each of the standard cells may include semiconductor elements. The semiconductor device may also include filler cells between two standard cells, and each of the filler cells may include a filler active region and a filler contact connected to the filler active region and may extend in the first direction. The semiconductor device may further include a lower wiring pattern electrically connected to at least one of the semiconductor elements and may extend into at least one of the filler cells in the second direction, and the filler contacts may include wiring filler contacts lower than the lower wiring pattern and connected to at least one of the lower wiring pattern.