The aim of this study is to develop a needs analysis scale for the Out-of-School Learning Environments (OSLE) course. An exploratory sequential mixed-methods design was used in the study. The qualitative phase of the study involved 34 experts, while the quantitative phase included 255 university students. In the first stage, the Delphi technique was utilized to determine the items of the Out-of-School Learning Environments Needs Analysis Scale. In the second stage, validity and reliability analyses were conducted. Specifically, Kaiser-Meyer-Olkin (KMO) coefficient, Bartlett's Test of Sphericity, Exploratory Factor Analysis (EFA), Cronbach's Alpha, item-total correlation, and Confirmatory Factor Analysis (CFA) were performed sequentially. Following Exploratory Factor Analysis (EFA), the final 42-item scale structure of Out-of-School Learning Environments Needs Analysis Scale (OSLENAS) was examined, revealing a two-factor structure. The Cronbach’s Alpha coefficient for the entire scale was calculated as 0.95, with the first sub-dimension ("Learning Outcomes") yielding 0.95, and the second sub-dimension ("Course Content") yielding 0.94. When these reliability coefficients were further evaluated and tested using Confirmatory Factor Analysis (CFA), it was confirmed that the Out-of-School Learning Environments Needs Analysis Scale has a two-factor structure. The scale serves as a valuable instrument for conducting the needs analysis of the OSLE course, providing evidence-based insights for curriculum planning and instructional improvements and assessing the competencies of education faculty students regarding their knowledge and skills required for out-of-school learning.