This landscape review was developed for MOMENTUM, a major USAID-supported health sector program, but is of interest to all capacity development practitioners. The review describes different levels and types of capacity that can be measured; clarifies the distinction between capacity and performance; identifies key capacity measurement tool types; and, assesses the suitability of different tool types for capturing capacities. Promising capacity measurement approaches that reflect the operational realities of complex environments are proposed. The landscape review uses a systems thinking, complexity-aware monitoring lens to examine linkages between capacity and performance improvement. Throughout the study, attention is also given to resilience as a key capacity at all levels of a system.