Philips' Evnia gaming monitor series include several monitors, out of which two use OLED panels. First up is the 42M2C5500W that is based on a 42-inch 138Hz 4K WOLED panel.
The second monitor is the 34M2C8600, which is based on a 34" curved 175Hz 3440x1440 QD-OLED panel (produced by SDC). The OLED monitors are now shipping globally.
The rest of the monitors are based on LCD displays, including the 34" 34M2C7600MV which uses a mini-LED display.
42" 4K WOLED / 34" 3440x1440 QD-OLED