Ms Bailey founded the campaign group Cure The NHS after being appalled by the care she witnessed her mother receive at the hospital before she died.
Probes into the scandal revealed that poor care could have led to the deaths of hundreds of patients as a result of maltreatment and neglect. Many were left lying in their own urine and excrement for days, forced to drink water from vases or given the wrong medication.
Speaking after the Buckingham Palace investiture ceremony, Ms Bailey said: "It's really exciting that I've received recognition for all the hard work, not only for myself but the group as well and everybody else within the NHS who's tried to speak out, whistleblowers from all over the country. It was a recognition that we've done the right thing."
After her mother Bella died in 2007 at Stafford Hospital, Ms Bailey campaigned to expose the major problems at Mid Staffordshire NHS Foundation Trust.
Her repeated calls for a public inquiry into the scandal came to fruition in 2010.