The past decade has witnessed tremendous advances in the synthesis of polymers that contain elements from the main groups beyond those found in typical organic polymers. Unique properties that arise from dramatic differences in bonding and molecular geometry, electronic structure, and chemical reactivity, are exploited in diverse application fields. Herein we highlight recent advances in inorganic backbone polymers, discuss how Lewis acid/base functionalization of polymers results in unprecedented reactivity, and survey conjugated hybrids with unique electronic structures for sensor and device applications. Polymers go main group! This Review shows how the incorporation of the full range of available main‐group elements into polymers leads to new functional hybrid materials with potential use in diverse application fields ranging from advanced elastomers, responsive gels, biodegradable materials, to organic electronics, imaging agents, sensors, and supported catalysts.