A novel uniplanar wideband magneto-electric dipole antenna element is proposed in this paper. The proposed antenna is composed of the conventional bow-tie radiation patch as an electric dipole, a semi-circular loop, which works as a magnetic dipole, a coplanar ground plane, two directors with different lengths for enhancing gain, and a microstrip-to-coplanar stripline transition balun. The designed antenna adopts a small-size coplanar ground plane to achieve a uniplanar structure. Consequently, this method reduces the space size immensely and makes the antenna suitable for the array application. In addition, a tapered slot structure is utilized to improve impedance matching. The prototype of the proposed antenna was fabricated and measured. The measured results keep in good accordance with the simulated ones. The simulated results show that the proposed antenna obtains a broad impedance bandwidth of 60.5% from 2.25 to 4.20 GHz (voltage standing wave ratio [VSWR] ≤ 2) which can be applied for wireless local area network (WLAN) (2.4–2.484 GHz), worldwide interoperability for microwave access (WiMAX) (2.5–2.69/3.4–3.69 GHz), and long term evolution (LTE) (2.5–2.69 GHz). Meanwhile, the stable gain, low cross-polarization, stable unidirectional radiation patterns, and low back lobe are obtained within the operating frequency band. The array composed of the proposed antenna elements is also investigated in this paper.