A compact multiband monopole antenna with four L-strips and microstrip feed is proposed for mobile phone, S-band, Wireless Local Area Networks, and X-band applications. The antenna is simulated on a Flame Retardant-4 (FR-4) epoxy substrate with a dielectric constant of (εr)= 4.4 and loss tangent of 0.01. The antenna is simulated using High-Frequency Structure Simulator (HFSS) software. The antenna consists of four L-shaped cuts in the patch, with the ground plane acting as the monopole radiator. The total miniaturized size of the antenna is 30 × 30 × 0.8 mm3, and the monopole ground plane size is 30 × 6 mm2. The proposed antenna has better performance in terms of total peak gain compared to other similar antennas. It is a compact and efficient antenna with good performance. It can be used for a variety of applications, such as mobile phones, wireless communication devices, and radar systems.