  Using DFT-based first-principles calculations, we demonstrate the tuning of
the electronic structure of Weyl semimetal SrSi$_{2}$ via external uniaxial
strain. The uniaxial strain facilitates the opening of bandgap along $\Gamma$-X
direction and subsequent band inversion between Si $p$ and Sr $d$ orbitals.
Z$_{2}$ invariants and surface states reveal conclusively that SrSi$_{2}$ under
uniaxial strain is a strong topological insulator. Hence, uniaxial strain
drives the semimetallic SrSi$_{2}$ into fully gapped topological insulating
state depicting a semimetal to topological insulator phase transition. Our
results highlight the suitability of uniaxial strain to gain control over the
topological phase transitions and topological states in SrSi$_{2}$.
