This paper presents a triple-band transparent flexible antenna for both 5G and ISM applications at 2.45 GHz, 3.8 GHz, and 5.7 GHz. The miniaturized proposed antenna (30 � 30 mm2) comprises two layers of polyimide as a substrate with a dielectric constant of 3.5 and a thickness of 0.125 mm. Furthermore, a tree shape transmission line and two rounded rectangular patches use Indium Tin Oxide (ITO) as a transparent conducting film while they are proximity coupled. The patches are cut by two rounded rectangular and J-shape slots to improve the radiation efficiency of the antenna. Besides, all antenna's parts are formed to obtain radiation efficiency > 83 at all the resonances, the gain of 3.27 dBi, 9.47 dBi, and 4.47 dBi at 2.45 GHz, 3.8 GHz, and 5.7 GHz respectively. Besides, the antenna shows a good agreement between simulation and measured results. © 2020 IEEE.