The masses of the strange mesons ($K$, $K^*$ and $phi$) are investigated in the presence of strong magnetic fields. The changes in the masses of these mesons arise from the mixing of the pseusdoscalar and vector mesons in the presence of a magnetic field. For the charged mesons, these mass modifications are in addition to the contributions from the lowest Landau energy levels to their masses. The decay widths, $phi rightarrow Kbar K$ and $K^* rightarrow Kpi$, in the presence of the magnetic field are studied using a field theoretic model of composite hadrons with constituent quarks/antiquarks. The model uses the free Dirac Hamiltonian in terms of the constituent quark fields as the light quark antiquark pair creation term and explicit constructions for the meson states in terms of the constituent quarks and anitiquarks to study the decay processes. The study of the masses and decay widths of the strange mesons in strong magnetic fields can have observable consequences on the production of the open and hidden strange mesons in the peripheral ultra high energy collisions at LHC, where the created magnetic field can be huge.