Disclosed are a light blocking device, a method of manufacturing the same, and a transparent display device including the same, which transmit or block light by using a polymer dispersed liquid crystal (PDLC) layer. The light blocking device includes a first substrate and a second substrate facing each other, a first electrode on the first substrate, a second electrode on the second substrate, and a PDLC layer between the first electrode and the second electrode. The PDLC layer includes a droplet including liquid crystals and dichroic dyes, and the liquid crystals and the dichroic dyes are twisted with each other and aligned.