Screen.currentResolution

説明

現在の画面の解像度（読み取り専用）

Returns the current screen resolution (read only). If the player is running in windowed mode, this returns the current resolution of the desktop. If you are working with VR devices, use XRSettings.eyeTextureWidth and XRSettings.eyeTextureHeight instead.

using UnityEngine;

public class Example : MonoBehaviour
{
    void Start()
    {
        print(Screen.currentResolution);
    }
}