This editorial article accompanies a Special Issue of Applied Thermal Engineering dedicated to the 33rd International Symposium on Transport Phenomena (ISTP-33) held from 24 to 27 September 2023 in Kumamoto, Japan. Following the symposium, the top 10% high quality papers based on the evaluation scores received in the peer-review process were selected by the organizing committee of ISTP-33. As a result of this procedure, 20 papers were invited to this Special Issue. The authors of 17 of these papers accepted the invitation to submit extended versions of their original papers presented at the symposium to this Special Issue, and these were peer-reviewed following the standard procedure in Applied Thermal Engineering. Finally, 13 research articles navigated the review process. and have been included in this Special Issue. This editorial briefly summarizes each article included in the Special Issue.