The development of a smart city (SC) has always been accompanied by urban innovation (UI). UI mainly refers to the use of smart technology to promote urban development and also as a product of SC development. Smart technology can be used and developed by SC citizens. However, some research on UI in SC is conducted mainly from top-down technocratic perspectives or citizen participation. Therefore, this study proposes that the level of citizen-centric UI can be measured by using the Unified Smart City Model (USCM). With the use of the systematic literature review method, a search was conducted using keywords on three literature databases. Fifty-six indicators of UI were compiled as preliminary findings, with eight of them categorised as USCM indicators—smart architecture, smart governance, smart planning and management, smart data and knowledge, smart facilities, smart services, smart people and smart environment—to develop a citizen-centric framework. This framework will facilitate the analysis of the UI level of SC to enable city comparison and identify areas of weakness to assist in city managers’ decision-making.