Sinha (90) breathed her last in a private hospital here.
She was wife of Congress stalwart and former Bihar Chief Minister Satyendra Narayan Sinha and mother of ex-Delhi police commissioner and former Kerala Governor Nikhil Kumar.
She was MP from Vaishali twice from 1980 to 1989 from Congress.
Condoling her death, Chief Minister Nitish Kumar announced state funeral for her.
He described her as a veteran politician and social worker.
Bihar Governor Ramnath Kovind, RJD President Lalu Prasad and state Congress President and minister Ashok Choudhary condoled death of Kishori Sinha.