Pierson, who succeeds Mark J Sullivan who retired last month, will take over at a time when the service is still to get over last year's prostitution scandal which made it a subject of public ridicule, led to Congressional hearings and even sacking of a number of agents.
Pierson, who has 30 years of experience in the secret service, will be facing a challenge to change the macho culture of the agency which will be under close eyes of Washington after the scandal which saw agents employing prostitutes in Colombia prior to Obama's visit.
Republican Senator Charles Grassley said the secret service had lost the trust of many Americans after the scandal and it will be interesting to see how the new director creates a new culture in the agency. Grassley hoped that the new chief will be successful in restoring the agency's pride.
Obama praised Pierson, saying she is "eminently qualified" to lead the secret service and banked hope on her, saying she will take on the new challenge. He did not mention about the scandal though.
Pierson's appointment does not require the Senate's confirmation.
The US Secret Service was formed in 1865 to curb counterfeit currency business. It was assigned with the task of protecting the presidents after the assassination of President William McKinley in 1901. Gradually, it started guarding former presidents, presidential nominees, visiting foreign leaders and other dignitaries.
The agency, however, has an under-representation of women. Of 3,500 special agents in the body today, only 10 per cent are women. The proportion of women members in the Secret Service uniformed division, which has the duty to protect the White House and other facilities, is tighter.