A variety of olefin-metathesis protocols have been used to prepare spirocyclic compounds, cyclic sulfones, and constrained α-amino acid derivatives. Conceptually, a new approach to a novel cyclophane ring system has been realized via ring-closing metathesis (RCM). Also, tetracyclic compounds related to anthracycline antibiotics have been assembled using Claisen rearrangement and RCM as key steps. Further, a sequential use of the Diels-Alder reaction and ring-opening cross-metathesis delivered highly functionalized spiroindane derivatives, and trisubstituted benzene derivatives have been assembled using Grubbs’ catalyst. Finally, the enyne and cross-enyne metathesis sequences have been used to prepare several constrained α-amino acid derivatives. 1 Introduction 2 Application of Ring-Closing Metathesis To Give Spirocyclic Compounds 3 Application of Ring-Closing Metathesis To Give Cyclophane Derivatives 4 Application of Ring-Closing Metathesis To Give Cyclic Sulfone Derivatives 5 Application of Ring-Closing Metathesis To Give Cyclic α-Amino Acid Derivatives and Modified Peptides 6 Application of Ring-Closing Metathesis to Benzannulation 7 Application of Enyne Metathesis to the Synthesis of Constrained α-Amino Acid and Naphthoxepin Derivatives 8 Application of Cross-Enyne Metathesis to the Synthesis of Highly Functionalized Phenylalanine Derivatives 9 Application of Ring-Opening Cross-Metathesis to Spiroindanes 10 Synthesis of Trisubstituted Benzene Derivatives Using Grubbs’ Catalyst 11 Metathesis of a Novel Enyne System 12 Macroheterocycles via Cross-Enyne and Ring-Closing Metathesis Cascade Reactions 13 Conclusions