In this study, it was aimed to develop a scale to determine English paragraph writing self-efficacy beliefs of university students. The scale was developed in three stages. In the first stage, literature review was conducted and expert opinions were taken. A trial form consisting of 45 items in Likerttype was prepared. Moreover, a pilot study was performed. In the second stage, the validity analyses were conducted on the data obtained from 428 university students. In the selection of the sample group to apply the scale, convenience sampling method was used. The construct validity of the developed scale was determined by the Explanatory Factor Analysis (EFA). The results supported a structure with two factors consisting of 33 items. The first factor was named as "Writing Process and Rules" and the second factor was named as "Self-Regulation". Additionally, Confirmatory Factor Analysis (CFA) was conducted to test whether the factors were correlated or uncorrelated. In addition, Pearson's coefficient of correlation analysis was used to find the relationship between all the factors of the English paragraph writing self-efficacy belief scale. In the last stage, reliability study was conducted. The Cronbach Alpha reliability coefficient for the first factor was found as 0.97, and 0.96 for the second factor. The total reliability coefficient for the scale was as 0.99. After all the analyses, the English paragraph writing self-efficacy belief scale consisting of 33 items and two factors was developed. The results showed that the scale is a valid and reliable measurement tool.