A high isolation magnetoelectric dipole antenna with wideband is presented based on low-temperature cofired ceramics processes. An L-shaped probe is used to excite magnetoelectric dipoles for realizing horizontal polarization. Meanwhile, another polarization is realized by a transmission line symmetrically crossing over the feeding slot of metal ground. Currents at two ends of a slot etched on the metal ground are excited and flow through the center of the L-shaped probe with a reversed phase. Therefore, the coupling currents between two orthogonal polarized ports are suppressed to realize high isolation. Therefore, the antenna element achieves impedance bandwidth of 29.7% from 23.6 GHz to 31.8 GHz and high isolation of more than 55 dB. Two single-layered microstrip line feeding networks are designed to configure with a 4×4 antenna array. The array obtains a impedance bandwidth of 30.3% from 23.6 GHz to 32.0 GHz and high isolation of more than -24 dB. In addition, the realized peak gain of two polarizations is 15.8 dBi and 16.3 dBi, respectively.