Building performance indicators are widely used to guide building design and track and benchmark operational performance. Traditional building performance indicators mostly focus on the energy efficiency perspective. Yet, the increasing penetration of renewable energy resources, distributed energy technologies, and frequent extreme weather events impose a need to quantify building energy flexibility and resilience to support research and development of grid-interactive efficient buildings (GEBs). One key factor to consider in the GEB context is occupant comfort and well-being, since occupants are the primary building service recipients in residential and most commercial buildings. This study first identified significant attributes of occupant-centric key performance indicators (KPIs) and analyzed the diverse factors that should be considered in formulating an occupant-centric KPI. Then a suite of occupant-centric KPIs were synthesized from the review and enhancement of existing occupant-related performance metrics. The proposed occupant KPIs represent the occupant lens on three integrative aspects of building performance: resource use (including energy and water), indoor environmental quality, and human–building interactions. A simulation-based case study was conducted to demonstrate how occupant-centric KPIs can be used to quantify the impacts of building operation changes from the occupants’ point of view.