In this paper, a semi-flexible antenna with low profile and broad-band characteristics used for the biomedical telemetry is proposed. The designed antenna is made up of semi-flexible RT/duroid 5880 material, which has a relative permittivity of 2.2 and a dielectric loss tangent of 0.0004, the antenna’s dimensions are 17.5 mm × 25.5 mm × 0.79 mm. By integrating rectangular slots into a conventional rectangular patch and modifying the partial ground plane, the antenna’s resonant frequency is lowered, and its operational bandwidth is enhanced. Operating at 2.42 GHz, the antenna model features a fractional bandwidth of 1300 MHz, which constitutes 59.7% centered around the 2.4 GHz frequency. With a high gain of 2.50 dBi and efficiency of 93% at 2.4 GHz, the proposed antenna demonstrates negligible degradation in return loss, fractional bandwidth, power gain, directive gain, and efficiency when subjected to bending, as validated by simulations and experimental data. Furthermore, the antenna’s performance remains unaltered and robust when simulated for the human body phantom model, indicating its suitability for compact wearable biomedical devices. Thus, the proposed wideband antenna emerges as a promising option for such applications.