This paper proposes a dual-band rectangular stub-loaded monopole antenna suitable for Sub - 6 GHz and IoT uses. The proposed antenna employs a rectangular radiating patch with two incorporated rectangular stubs and two rectangular slots to provide wideband impedance matching and dual-frequency operation. The antenna is fabricated on a Roger RO3003 substrate on compact dimensions of 50 × 50 × 1.524 mm³ along with a 50 Ω microstrip feedline to effect good impedance matching. The measured S₁₁ results have shown two distinct operating band: 2.2GHz–2.6 GHz and 3.0GHz–4.9 GHz, with an exceptional return loss of –68.57 dB at 4.22 GHz, exhibiting excellent impedance matching. The suggested antenna exhibits a top gain of 2.72 dBi & total efficiency up to 97.8% that promises very good radiation performance. Due to its small size, high efficiency, and excellent impedance characteristics, the antenna is highly appropriate for IoT, WLAN, and Sub-6 GHz wireless communication systems.