In this paper, we propose a generalized notion of a distance function, called a g-metric.The g-metric with degree n is a distance of n + 1 points, generalizing the ordinary distance between two points and G-metric between three points. Indeed, it is shown that the g-metric with degree 1 (resp. degree 2) is equivalent to the ordinary metric (resp. the G-metric). Fundamental properties and several examples for the g-metric are also given. Moreover, topological properties on the g-metric space including the convergence of sequences and the continuity of mappings on the g-metric space are studied. Finally, we generalize some well-known fixed point theorems including Banach contraction mapping principle and Ćirić fixed point theorem in the g-metric space.