Limonene is a valuable natural product with diverse applications in food, pharmaceutical, paints and coatings, chemicals, etc. Commercial production of limonene based on extraction from plants is economically inviable to meet the ever-growing market demand. Metabolic engineering and synthetic biology offer a promising and sustainable way to produce limonene in microbes. Massive works have been done to promote the limonene bio-production efficiency of microbial cell factories toward economic viability. This chapter provides a comprehensive overview of recent progress in engineering microorganisms for limonene biosynthesis with special attention to bottleneck engineering, microbial host choosing, and limonene cytotoxicity.