The Golgi apparatus in vertebrate cells consists of individual Golgi stacks laterally fused together in a continuous ribbon structure. The ribbon structure per se is not required to mediate the classical functions of this organelle and the relevance of the “ribbon” structure has been a mystery since first identified ultrastructurally in the 1950s. Recent advances are now recognising a role for the Golgi apparatus in a range of cellular processes, and our current studies are investigating whether the ribbon structure of the Golgi may contribute to the regulation of additional cellular processes. We have developed a cell system to explore the function of the Golgi ribbon by exploiting a finding that the membrane tether of the trans-Golgi network, GCC88, regulates the balance between Golgi mini-stacks and the Golgi ribbon in a variety of cell types. We have shown that the regulation of Golgi morphology by GCC88 is an actin dependent process and have identified GCC88 interactive partners responsible for connecting GCC88 to actin filaments. Loss of Golgi ribbons in stable HeLa cells overexpressing GCC88 resulted in a dramatic increase in LC3-II-positive autophagosomes and compromised mechanistic target of rapamycin (mTOR) signalling, whereas RNAi depletion of GCC88 restored a Golgi ribbon and reduced autophagy. In parental cells mTOR was detected on both the Golgi and lysosomes. There was a dramatic reduction in Golgi associated mTOR and phosphorylated active mTOR in HeLa cells lacking a Golgi ribbon compared with parental cells. We demonstrate a strict temporal sequence of fragmentation of Golgi ribbon, loss of Golgi mTOR followed by increased autophagy. Golgi ribbon fragmentation has been reported in various neurodegenerative diseases and we have demonstrated the potential relevance of our findings in neuronal cells using a model of neurodegeneration. Overall, our results have uncovered a mechanism by which the Golgi ribbon negatively regulates autophagy by modulating mTOR signalling.