On‐surface synthesis represents a chemical approach whereby molecular building blocks holding adequate functional groups are dosed onto surfaces that support or even drive their covalent linkage. The new environment created by the surface confinement and the frequent lack of solvents (most commonly being performed under vacuum conditions) makes this approach fully complementary to conventional chemistry. Among the many differences that this brings, one can find original reaction mechanisms, as well the absence of solubility or chemical instability problems when working under vacuum, each opening new doors to the synthesis of novel materials. Examples thereof include the linear polymerization of alkanes, access to an increasingly large pool of differently structured graphene nanoribbons with atomic precision, or elusive molecules like higher acenes or triangulene.