The quantum Hall effect (QHE), a quantum phenomenon observed on a macroscopic scale, has been studied extensively since its discovery in 1980. It is unique to two-dimensional (2D) metals and has provided insights into quantum physics and interacting systems. The QHE requires low temperatures, typically below the boiling point of liquid helium. However, efforts to extend the QHE to higher temperatures have been limited, with the highest observed temperature being around 30K. This study demonstrates that the QHE can be observed in graphene at room temperature due to the unique properties of charge carriers in graphene, which behave as massless relativistic particles (Dirac fermions) with minimal scattering under ambient conditions. Figure 1 shows the room-temperature QHE in graphene. The Hall conductivity σxy exhibits clear plateaux at 2σ²/h for both electrons and holes, while the longitudinal conductivity ρxx approaches zero, indicating an activation energy of approximately 600K. The quantization of σxy is accurate within 0.2%. The survival of the QHE at high temperatures is attributed to the large cyclotron gaps in Dirac fermions in graphene. The energy quantization in a magnetic field B is described by E_N = ν_F√|2ħBN|, where ν_F is the Fermi velocity and N is an integer Landau level number. This results in an energy gap of approximately 2800K at B = 45T. The QHE in graphene is also supported by high carrier concentrations and high mobility of Dirac fermions, which remain stable from liquid helium to room temperature. These characteristics suggest that the room-temperature QHE can be observed in magnetic fields significantly smaller than 30T. The study opens new possibilities for developing graphene-based resistance standards and quantum devices operating at elevated temperatures.The quantum Hall effect (QHE), a quantum phenomenon observed on a macroscopic scale, has been studied extensively since its discovery in 1980. It is unique to two-dimensional (2D) metals and has provided insights into quantum physics and interacting systems. The QHE requires low temperatures, typically below the boiling point of liquid helium. However, efforts to extend the QHE to higher temperatures have been limited, with the highest observed temperature being around 30K. This study demonstrates that the QHE can be observed in graphene at room temperature due to the unique properties of charge carriers in graphene, which behave as massless relativistic particles (Dirac fermions) with minimal scattering under ambient conditions. Figure 1 shows the room-temperature QHE in graphene. The Hall conductivity σxy exhibits clear plateaux at 2σ²/h for both electrons and holes, while the longitudinal conductivity ρxx approaches zero, indicating an activation energy of approximately 600K. The quantization of σxy is accurate within 0.2%. The survival of the QHE at high temperatures is attributed to the large cyclotron gaps in Dirac fermions in graphene. The energy quantization in a magnetic field B is described by E_N = ν_F√|2ħBN|, where ν_F is the Fermi velocity and N is an integer Landau level number. This results in an energy gap of approximately 2800K at B = 45T. The QHE in graphene is also supported by high carrier concentrations and high mobility of Dirac fermions, which remain stable from liquid helium to room temperature. These characteristics suggest that the room-temperature QHE can be observed in magnetic fields significantly smaller than 30T. The study opens new possibilities for developing graphene-based resistance standards and quantum devices operating at elevated temperatures.