Investment in outdoor parks is proposed as a promising large-scale strategy to promote physical activity (PA). This study aimed to systematically review the impact of park renovations or installing new ones in increasing PA. Searches were conducted using predefined terms in three databases (PubMed, Scopus, and Web of Science) in March 2022. Studies examining the effectiveness of park renovations or developing new ones in increasing PA and having control or comparison were eligible for inclusion. Study quality was assessed using the Quality Assessment Tool for Quantitative Studies. Data were extracted from the included records using a predefined extraction table. The database search yielded 959 records, and 26 were included. For park renovations (n = 17), 11 (65%) studies presented findings supporting a positive effect on PA. The other six (35%) studies found no PA benefits when compared to control or pre-renovations/improvement levels. Regarding new installations (n = 9), five (56%) studies presented improvements in PA, and four (44%) did not. A promising positive impact of park renovations and new installations on park use and PA was observed. The review findings reflect the need to understand the context, daily routines, and interests of the surrounding population before renovating or installing new outdoor parks.