Integrated circuit devices including standard cells are provided. The standard cells may include a first vertical field effect transistor (VFET) having a first conductivity type, and a second VFET having a second conductivity type. The first VFET may include a first top source/drain region, a first channel region, and a first bottom source/drain region. The second VFET may include a second top source/drain region, a second channel region, and a second bottom source/drain region. The standard cells may also include a conductive line that is electrically connected to the first top source/drain region or the first bottom source/drain region and is electrically connected to the second bottom source/drain region. The standard cell may be configured to output an output signal thereof through the conductive line.