By solving the infinitesimal Galilean symmetry for the Korteweg-de Vries (KdV) hierarchy, we obtain an explicit expression for the corresponding one-parameter Lie group, which we call the Galilean symmetry of the KdV hierarchy. As an application, we establish an explicit relationship between the non-abelian Born-Infeld partition function and the generalized Br & eacute;zin-Gross-Witten partition function.