In this paper, we study the local gradient regularity of non-negative weak solutions to doubly nonlinear parabolic partial differential equations of the type \(\begin{aligned} \partial _t u^q - {{\,\textrm{div}\,}}A(x,t,Du)=0 \qquad \text{ in }~\Omega _T, \end{aligned}\) with \(q>0\) , \(\Omega _T:=\Omega \times (0,T)\subset \mathbb {R}^{n+1}\) a space-time cylinder, and \(A=A(x,t,\xi )\) a vector field satisfying standard p-growth conditions. Our main result establishes the local Hölder continuity of the spatial gradient of non-negative weak solutions in the super-critical fast diffusion regime \(\begin{aligned} 0<p-1<q<\frac{n(p-1)}{(n-p)_+}. \end{aligned}\) This result is achieved by utilizing a time-insensitive Harnack inequality and Schauder estimates that are developed for equations of parabolic p-Laplacian type. Additionally, we establish a local \(L^\infty \) -bound for the spatial gradient.
