An organic light emitting display device may include a filling part filling a space between a second substrate and an organic light emitting diode, and a dam structure disposed in a non-display area and surrounding the filling part. At least one of the dam structure and the filling part includes a getter. The getter of the present disclosure is composed of magnesium oxide particles whose surfaces are modified into a first surface modification part made of an amino silane-based compound and a second surface modification part bound to the first surface modification part and made of a compound containing an acrylate group and a methacrylate group. Accordingly, it is possible to provide an organic light emitting display device that has high transparency and of which optical properties and durability are improved by minimizing permeation of water and oxygen.