The In Plain Sight star reveals the cause is close to her heart because her husband Michael Morris suffers from Type 1 diabetes.
McCormack is aiming to raise $25,000 (£15,625) for the Juvenile Diabetes Research Foundation (JDRF) research centre with her fundraising page on the website CrowdRise.com.
In a post on the page, she writes, "I care dearly about spreading awareness and funding research for type 1 diabetes (T1D) through JDRF. My husband has T1D, and this issue hits so close to home. Did you know that as many as three million Americans may have T1D? This is an unbelievable statistic! Each year, more than 15,000 children and 15,000 adults, approximately 80 people per day, are diagnosed in the U.S."
Fans who donate to the cause will be entered into drawings to win prizes including a signed West Wing script, an iChat call with actress Jenny McCarthy and tickets to see the Chelsea Handler Show.