The American, who was the automaker's first female managing officer, has been appointed to a senior media adviser for Toyota Motor North America as of June 20, a Toyota spokesperson said.
She will assist media relations and ESG response in addition to supporting the automaker's president, Akio Toyoda.
Toyota does not see Hamp's appointment as a problem since she was not indicted, the spokesperson said.
Hamp, a former General Motors Co and PepsiCo Inc executive, assumed the title of managing officer and chief communications officer in April 2015.
Joining Toyota's North American unit in 2012, her promotion was part of an endeavour to bring in women and non-Japanese nationals into a male-dominated, mostly Japanese executive line-up.
Hamp was arrested in June 2015, shortly after relocated to Japan, when custom officials found tablets of oxycodone in a parcel shipped to her from the United States.
She said at that time she did not think she had imported an illegal substance, and Toyota said it believed that she had no intent of breaking the law.
Nevertheless, she stepped down from the position. She was released from custody and prosecutors did not indict her in the following month.
(Reporting by Satoshi Sugiyama; editing by Jason Neely)