A wide band terahertz dipole-antenna using graphene with tunable resonant frequency is proposed. Presence of graphene in the antenna is shown to electrically tune resonant frequency and to push the antenna to resonate with multibands in terahertz regime. The proposed terahertz antenna shows maximum of five tuning frequencies and better performance parameters such as return loss of −  39.7 dB, maximum directivity of 9.3 dB, five resonant tuning frequencies (multi resonances) at chemical voltage of 0.5 eV, maximum fractional bandwidth of 15.6%, maximum radiation efficiency of 21.5% and large bandwidth of 2.32 THz. Large bandwidth of the antenna can be very useful for highest possible data transfer among wireless devices. The proposed graphene based terahertz antenna has the dimensions of few micrometers so miniaturization i.e. size is reduced to 0.007 mm² which is suitable for size limited future applications such as Wireless Networks on Chip, software defined meta material and Wireless Nano Sensor Networks (WNSNs). Size of the proposed terahertz antenna is less than that reported in the literature. One reconfigurable and miniaturized antenna may replace a number of single function radiators, thereby also cost and size of a WNSNs can be abridged while performance is improved.