Peri-urban and urban green are considered among the basic priorities of the local government’s regional policy agenda, in line with the principles of spatial planning. This agenda is promoted at both the national and European levels through a variety of technical and institutional measures. Green spaces in urban and suburban areas are directly linked to the quality of life of urban residents and their environment. In this context, the purpose of this study is to investigate and identify the characteristics and factors that influence the residents of a small Greek city in terms of the value they attach to urban and suburban green spaces. These factors are identified through the residents’ willingness to pay (WTP) using the contingent valuation method (CVM). In general, the analysis aims to document the value of environmental economic methods as a tool in the management of natural heritage. According to the research, income and knowledge of environmental issues (global and local) as well as the benefits of green spaces (urban and suburban) are the key factors that drive residents to place a higher value on them. Future work may explore whether or how the COVID-19 pandemic affected city residents’ willingness to pay for green spaces.