Sphingolipids constitute a ubiquitous class of lipids present in all eukaryotes as well as in several prokaryotes and even some viruses. Their structure is peculiar among other classes of lipids with a backbone made of a sphingoid base bearing an N-linked fatty acid. This structure, known as ceramide, is further modified by means of polar head substitutions. Head substitutions, fatty acids of different lengths and sphingoid bases variants generate a great assortment of sphingolipid isoforms (sphingolipidome), which is highly diversified between organisms, kingdoms and cell types. Sphingolipids are essential for organism development and cell growth since complex sphingolipids are major components of biological membranes and involved in membrane domain organization and receptor signaling. Sphingoid bases are instead involved in cell signaling, cell growth and stress responses. Several key enzymes of the biosynthetic pathway are highly conserved and finely regulated to generate key "structural orthologs" that seem to be shared among organisms. In this chapter, we describe step by step the sphingolipid biosynthetic pathway, and via a continuous parallel between plant, yeast and animal, we will review the sphingolipid functions in different organisms and cells.