Tomas Thiel is a Swedish urologist and clinical researcher based in Stockholm. He works at the Division of Urology, part of the Department of Clinical Science, Intervention and Technology (CLINTEC) at the Karolinska Institutet, and practices at the Karolinska University Hospital Huddinge.

His clinical and research focus includes uro-oncology, particularly non–muscle-invasive bladder cancer and renal tumors. He has contributed to multiple peer-reviewed publications on intravesical BCG therapy, imaging in acute renal colic, and minimally invasive management of small renal masses.

Dr. Thiel is also involved in teaching and mentoring medical students and residents at Karolinska. He actively participates in clinical studies aimed at improving diagnostic and therapeutic strategies in urology.