Seetharam, who was elected from Amadalavalasa constituency in Srikakulam district, was declared elected to the post by the Protem Speaker C. Appala Naidu on the second day of the first session of the new state Assembly.
Seetharam was elected unopposed since only he had filed the nomination for the post of Speaker.
Chief Minister Y.S. Jagan Mohan Reddy, opposition Telugu Desam Party (TDP) MLA Atchan Naidu and others greeted Seetharam and accompanied him to the chair.
TDP president N. Chandrababu Naidu also congratulated Seetharam and recalled that the latter had entered politics during his student days, responding to a call given by TDP founder N. T. Rama Rao.
Seetharam, a six-time MLA, began his political career with the TDP. He served as a minister in the cabinets of both N. T. Rama Rao and Chandrababu Naidu in 1980s and 1990s.
He had joined the Praja Rajyam Party floated by actor Chiranjeevi in 2009 but lost the elections. In 2013, he joined YSRCP but was again defeated in 2014.
The 64-year-old was elected as a YSRCP candidate in the recent elections. He is the fourth leader from Srikakulam to become the Speaker.