Lawan also appointed Muhammad Aji as chief of staff.
In a statement on Tuesday, Betty Okoroh, special adviser to the senate president on administration, said the appointments were made on merit.
“The appointments were made based on merit, experience, track record and competency of Aji and Adedayo needed by the Senate President in executing his planned legislative agenda,” she said.
Adedayo has a PhD in political communication from University of Ibadan and a member of editorial board of Tribune newspapers.
Adedayo was media adviser to Abiola Ajimobi and Chimaroke Nnamani, former governors of Oyo and Enugu.
Aji holds a master’s degree in educational planning and administration and another one in public administration – both from university of Maiduguri.
He is a member of several professional bodies, including the Nigerian Institute of Management (NIM) and Registered Administrative Managers of Nigeria.