In recent decades cancer incidences and mortality rates have increased. Although there is significant progress in identifying the root causes and emerging therapies, there are many molecular, cellular mechanism’s unrevealed and current treatments have yet to deliver on their promises. Common characteristics of cancer that are controlled by various mechanisms, including those involving glycosylation-dependent proliferative signalling, the ability of tumor cells and their microenvironment to sustain proliferative signalling, enhancing the replicative immortality, evading the effects of growth suppressors, resisting apoptosis, sustaining invasion and metastasis, stimulation of angiogenesis and triggering immune response are few to name. An evolutionarily conserved family of glycan-binding proteins known as galectins has a significant impact in controlling these cascades. Galectins belong to animal lectin family that function by interacting with matrix glyco-proteins on extracellular surface and also with nuclear proteins modulating the cell signalling cascades intracellularly. In this review, we analyse how galectins influence the cellular pathways that control tumor activity, providing relevant examples and highlighting their therapeutic perspective in the fight against cancer.