We study the arboricity A and the maximum number T of edge‐disjoint spanning trees of the classical random graph G(n,p). For all p(n)∈[0,1], we show that, with high probability, T is precisely the minimum of normalδ and true⌊m/(n−1)true⌋, where normalδ is the minimum degree of the graph and m denotes the number of edges. Moreover, we explicitly determine a sharp threshold value for p such that the following holds. Above this threshold, T equals true⌊m/(n−1)true⌋ and A equals true⌈m/(n−1)true⌉. Below this threshold, T equals normalδ, and we give a two‐value concentration result for the arboricity A in that range. Finally, we include a stronger version of these results in the context of the random graph process where the edges are randomly added one by one. A direct application of our result gives a sharp threshold for the maximum load being at most k in the two‐choice load balancing problem, where k→∞.