We demonstrate a GaN:Eu,O-based resonant-cavity light emitting diode (RCLED) fabricated with a n-type conductive Al 0.82 In 0.18 N/GaN bottom-distributed Bragg reflector (DBR) and a ZrO 2 /SiO 2 top-DBR and made in order to manipulate both the radiative transition probability of Eu 3+ ions and the light extraction efficiency. Shortening of the lifetime of Eu-related luminescence, along with an improved directionality of the light output, is observed from the RCLED. These factors lead to a 4.8 times enhancement of the output power at room temperature as well as a peak enhancement of the electroluminescence intensity of 10.9 as compared to a conventional GaN:Eu,O-based LED. This is the first demonstration of the red RCLED based on rare-earth-doped GaN and enables a significant enhancement of Eu luminescence of the GaN:Eu,O-based red LED with a high color purity and temperature insensitive emission wavelength.