This study investigates the photocatalytic hydrogen evolution of a high-entropy oxide (HEO) synthesized by a mechano-thermal method. The HEO, TiZrNbHfTaOₓ, was produced through mechanical alloying and subsequent mechano-thermal oxidation. The synthesized material exhibited a bandgap of 2.45 eV, suitable for both UV and visible light regions. Under light exposure, the HEO successfully produced hydrogen from water without the need for a co-catalyst, with hydrogen production increasing over time. After 3 hours, the hydrogen production rate reached 134.76 μmol/m² h. This study not only introduces a new method for producing high-entropy photocatalysts but also confirms the potential of these materials for efficient hydrogen production without the need for precious metal co-catalysts. The findings highlight the advantages of high-entropy photocatalysts in terms of uniform element distribution and fully oxidized cations, which contribute to their superior photocatalytic performance.This study investigates the photocatalytic hydrogen evolution of a high-entropy oxide (HEO) synthesized by a mechano-thermal method. The HEO, TiZrNbHfTaOₓ, was produced through mechanical alloying and subsequent mechano-thermal oxidation. The synthesized material exhibited a bandgap of 2.45 eV, suitable for both UV and visible light regions. Under light exposure, the HEO successfully produced hydrogen from water without the need for a co-catalyst, with hydrogen production increasing over time. After 3 hours, the hydrogen production rate reached 134.76 μmol/m² h. This study not only introduces a new method for producing high-entropy photocatalysts but also confirms the potential of these materials for efficient hydrogen production without the need for precious metal co-catalysts. The findings highlight the advantages of high-entropy photocatalysts in terms of uniform element distribution and fully oxidized cations, which contribute to their superior photocatalytic performance.