In this paper, a miniaturized triple-band gap multi-via electromagnetic band gap (TBMV-EBG) structure is proposed. Lumped LC modelling method is used for the analysis of the proposed TBMV-EBG structure. Triple band gaps in both x and y-directions are obtained since TBMV-EBG unit cell consists of three resonance parallel LC circuits. Ansys (HFSS) simulation is used in eigen mode to simulate a unit cell of the proposed EBG. There is a strong agreement between simulated and experimental results. Comparing the proposed TBMV-EBG with triple band slotted EBG, triple band CSRR-EBG, fractal EBG, and dual band split EBG, size reductions of 6.52%, 7.53%, 23.21%, and 25.86% are obtained respectively which is validated by simulated and experimental results. Demonstration of the proposed TBMV-EBG structure for ultra-wideband (UWB) application is also presented. Simulation and measurement results prove that by using a single TBMV-EBG cell at the feed line of a UWB monopole antenna triple band-notches can be obtained. Moreover, switching characteristics of the proposed antenna are also demonstrated using single P-IN diode. Depending on the ON and OFF switching status of P-IN diode, the UWB antenna provides switching from triple band-notches to dual band-notches, respectively. The proposed switchable monopole UWB antenna as a single unit can be useful in applications wherein switching between multi-bands is desirable without changing the geometry of the structure.