Mark C. Deleon, MD

Mark C. Deleon, MD

Medical Oncology, Hematology
Medical Group
Ascension Medical Group
Ascension Medical Group Ascension Medical Group
Languages Spoken


Mark DeLeon, MD, is a board-certified medical oncologist and hematologist with Ascension Sacred Heart. He provides personalized, compassionate to patients with cancer or diseases of the blood. Dr. DeLeon has a special interest in general hematology, anemia, multiple myeloma, and lymphoma, as well as breast, lung, colorectal and prostate cancer. For patients with advanced malignancies, he is passionate about palliative care efforts and balancing treatment guidelines with quality of life goals and values. Throughout his career, Dr. DeLeon has held a variety of leadership positions, including chief of staff and member of the board of trustees for Hill Country Memorial Hospital in Fredericksburg, Texas, as well as department chair of hematology and oncology at Wilford Hall Medical Center in San Antonio and member of the executive committee for Cancer Care Centers of South Texas. He served for 17 years in the U.S. Air Force, where he achieved the rank of Lt. Colonel at Wilford Hall Medical Center in San Antonio. Outside of the office, Dr. DeLeon enjoys cycling, playing Pickleball and spending time with his family.



  • Uniformed Services University (USUHS)


  • S.A. Uniformed Services Health Educ. Consortium


  • Wilford Hall Medical Center


  • Wilford Hall Medical Center


Hospital Affiliations

  • Ascension Sacred Heart Hospital Bay
  • Ascension Sacred Heart Hospital Emerald Coast


  • The American Board of Internal Medicine - Hematology
  • The American Board of Internal Medicine - Medical Oncology


Why Ascension
Ascension doctors are committed to getting to know you. They take time for real back-and-forth conversations with you so they can understand all aspects of you and your life. Because great care starts with seeing your whole picture.
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