Judge of Aizawl Bench of the Gauhati High Court Justice L S Jamir administered the oath of office to Paul at a function at the Aizawl Raj Bhavan Durbar Hall.
The swearing-in ceremony was attended by Chief Minister Lal Thanhawla, his cabinet colleagues, legislators and top officials.
Earlier, Paul arrived at the Lengpui airport near Aizawl where he was accorded a ceremonial guard of honour in the presence of Lal Thanhawla, Home minister R Lalzirliana, Education minister H Rohluna, Sports Minister Zodintluanga, state chief secretary L Tochhawng and other top officials.
Duggal had submitted his resignation on August 27.
Student organisations in Mizoram have been protesting against the Centre saying that the gubernatorial post of Mizoram has been made like a musical chair.
Mizoram Governor Vakkom Purushothaman was transferred from Mizoram to Nagaland by the NDA government on July six, but he refused to occupy the Kohima Raj Bhavan and submitted his resignation on July 11.
Governor of neighbouring Manipur Vinod Kumar Duggal, was appointed as the Mizoram governor on the day Beniwal received the marching orders.
Maharashtra Governor Kateekal Sankaranarayanan was transferred to Mizoram on August 23 to replace Duggal.
However, Sankaranarayanan refused to be transferred to Mizoram and resigned on August 24.
