Mr Wako’s wife and son have also been barred.
“Today’s action sends a strong signal that the United States is a valuable partner in Kenya’s fight against corruption,” said a statement from the US State Department.
Mr Wako has yet to react to the US announcement.
In 2009, the US imposed a travel ban on Mr Wako saying he was blocking political reforms in Kenya that were put in place after the violence that followed the 2007 election.
At the time Mr Wako denied the allegations and threatened to sue the US.
The 73-year-old served as Kenya’s attorney general from 1991-2011.
He is currently a senator as well as a member of the Building Bridges Initiative – a 14-member team put together by President Uhuru Kenyatta and opposition leader Raila Odinga aimed at addressing issues that could spark political violence in Kenya.