Thermal stability and optical transparency are important factors for flexible electronics and heat-related applications of pressure-sensitive adhesives (PSAs). However, current acryl- and rubber-based PSAs cannot attain the required thermal stability, and silicon-based PSAs are much more expensive than the alternatives. Oleo-chemicals including functionalized plant oils have great potential to replace petrochemicals. In this study, novel biobased PSAs from soybean oils were developed with excellent thermal stability and transparency as well as peel strength comparable to current PSAs. In addition, the fast curing (drying) property of newly developed biobased PSAs is essential for industrial applications. The results show that soybean oil-based PSA films and tapes have great potential to replace petro-based PSAs for a broad range of applications including flexible electronics and medical devices because of their thermal stability, transparency, chemical resistance, and potential biodegradability from triglycerides.