Sustainable fashion is clothing and accessories that, while maintaining the indicators of beauty, creativity, and art in fashion, achieve the three goals of sustainable development, including environmental, economic, and social. Fish skin, as a sustainable raw material, has been separated from its original function in the not-so-distant past and, despite the increase in production volume, is generally left in nature, which is environmentally destructive or has a low value-added use, but it has recently attracted the attention of leading global brands such as Dior and Galliano. In Iran, due to the high volume of fish and its skin production, this sustainable raw material is not known and no comprehensive research has been conducted to investigate its characteristics. Accordingly, in order to investigate the characteristics and specifications of fish leather produced in Iran and to assess its suitability for use in clothing production, based on National Standard 78, nine practical tests such as tensile strength, tear strength, and rubbing test were conducted on tilapia leather produced in Iran. A comprehensive comparison with other natural leathers and international standards was then conducted to introduce this sustainable and innovative material to the Iranian apparel industry. The research findings showed that tilapia leather produced in Iran has good mechanical strength, durability, and aesthetic quality, which can make it a suitable and sustainable alternative material for use in apparel and fashion accessories.