One field of organometallic chemistry that has seen great advancements over the last 20 years is that of main-group chemistry, in particular boron chemistry, that has led to a wealth of new discoveries. In this review, we will focus on modern advancements in this growing field, such as interesting uses of firmly established reagents, such as tris(pentafluorophenyl)borane, B(C6F5)3, which has demonstrated extensive applications in a wide variety of chemistry. In addition to this, a number of novel Lewis acidic boranes and borocations have been recently synthesised, which are often structurally tailored for a specific role such as borylation reactions or use in main-group catalysis. The reactions of these compounds are broad in scope, inclusive of borylation substitution reactions, addition of B–E across π-bonds and applications in pharmaceuticals and materials science. In addition, boron reagents often constitute the Lewis acid moiety of frustrated Lewis pairs (FLPs), an area of main-group chemistry that has also expanded rapidly, with numerous applications notably in main-group catalysis. Newly discovered Lewis acidic boron reagents and their implementations are proving to be an appealing and exciting applications-based field as more advances are discovered.