Construction profession continues to play a leading role in infrastructural development as witnessed in ongoing building and civil engineering projects. Adequate awareness of relevant principles in Applied Geology is essential, particularly in determination of geotechnical suitability of construction sites, geology of excavations of quarries, damsites and tunnels, and geomaterials to be used in construction works while addressing environmental concerns. It is on this basis that the contents provided in this lecture manual book have been compiled while addressing syllabus requirements for pertinent diploma and degree programmes. Topics covered herein provide knowledge and practical skills on; geology of excavations, hydrogeology and geomaterials in engineering service; apart from knowledge on geohazards mitigation and disaster preparedness. A competency-based approach was adopted so as to alert the reader on learning outcomes that are expected for each topic. The questions and solutions provided will enable the reader to appreciate the significance of Applied Geology in the design process of construction projects thus making the lecture manual self-reliant to the learner.