Maryland Oncology Hematology remains open while making accommodations for the health and safety of our patients. If you believe you have been exposed to COVID-19 or have symptoms of COVID-19 including fever, cough, sore throat or shortness of breath, please call our office before you arrive. Any patient that has traveled out of state, please call before your appointment for travel information and review our travel policy. Our Mt. Airy location is now open and Wheaton patients now call Rockville & Germantown. View more information.


Shannon C. O’Connor, M.D.

Shannon O'Connor, M.D.


Medical Oncology


9905 Medical Center Drive, Suite 200
Rockville, MD 20850-6535
Phone: 301-424-6231
Fax: 301-294-4648
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20330 Seneca Meadows Parkway Suite B Germantown, MD 20876
Phone: 301.424.6231
Fax: 301.279.9169
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Shannon O'Connor, M.D.


Georgetown University

Medical School

St George's University School of Medicine


Georgetown University, Washington Hospital Center


Georgetown University, Washington Hospital Center


Hematology & Oncology, Georgetown University, Washington Hospital Center

Board Certification

  • Hematology
  • Medical Oncology
  • Internal Medicine


  • American Society of Clinical Oncology
  • American Society of Hematology
  • Montgomery County Medical Society
  • American Medical Association


Board Certified in Hematology and Medical Oncology, Dr. O’Connor is a native of the Washington DC metro area. Her established practices are located in Rockville and Bethesda. She has a special focus in Women’s health including breast cancer, gynecologic cancers and hematologic conditions. She stayed local for her undergraduate work at The George Washington University and then received her Master’s Degree in Physiology at Georgetown University. After receiving her medical degree at St. George’s University, Dr. O’Connor completed her internship, medical residency and fellowship in hematology/oncology at Georgetown University/Washington Hospital Center. She is active on the breast cancer committee at Shady Grove Adventist Hospital and is completing her certification in Genetics.

On a personal note, she enjoys spending time with her 2 small children and husband doing outdoor activities such as cycling, paddle boarding and trapeze. She enjoys vacationing with her family and friends at the beach as well.