The first black woman to become a Church of England bishop will be consecrated during a ceremony at St Paul's Cathedral.
In June it was announced chaplain to the speaker of the house, The Rev Dr Rose Hudson-Wilkin, will be the new Bishop of Dover.
She said she feels a "bit like a bride" ahead of Tuesday's consecration.
Dr Hudson-Wilkin succeeds the Rt Revd Trevor Willmott who retired from the role in May.
She was 14 when she joined the ministry and said she never thought becoming a bishop would be possible.
Dr Hudson-Wilkin, who is also a chaplain to the Queen, led prayers at the wedding of Prince Harry and Meghan Markle in May 2018.
She said: "When I was first called into ministry women weren't even allowed to be ordained, so Bishop was not in my frame of reference.
"I'm feeling a bit like a bride. All the pensive moments but also equally excited, a sense of awe and a sense of perhaps 'is this real?'"