This paper presents a continuously tunable microstrip patch antenna formed from liquid metal (eutectic gallium indium). The concept and design of the antenna have been validated through computer simulation. The antenna is capable of reconfiguring its operating frequency in a continuous manner. The proposed design consists of a microstrip patch which is excited via aperture coupling. The EGaIn liquid metal is contained within a microfluidic channel which is formed within a polydimethylsiloxane (PDMS) substrate. Frequency tuning is achieved by altering the amount of fluid within the channel to vary the electrical length of the antenna. The simulated antenna provides a frequency tuning range of approximately 104% and a total usable spectrum (S11 <; -10 dB) of 105%. The antenna can be tuned from 3.21 GHz to 10.12 GHz. The maximum realized gain is 6.9 dBi and the total efficiency is 82%.