An optical sheet includes a reflective polarizer and a filter layer. The reflective polarizer reflects a part of incident light and transmits another part of the incident light. The filter layer selectively reflects the transmitted light passed through the reflective polarizer. The filter layer reflects at least one of a first wave band that is an overlapped area between a green peak and a blue peak in the spectrum of incident light, and a second wave band that is an overlapped area between a green peak and a red peak in the spectrum of incident light.