Yes, you can shrink a leather jacket. Use only gentle methods like light water dampening or low heat. Never soak or overheat the leather - it will crack. Wear the jacket as it dries for a custom fit. For best results, take it to a professional tailor. Always condition the leather after shrinking. Differenttypes react differently, so test first.https://www.leatherscin.com/blog/how-to-shrink-a-leather-jacket/