Padmanābhan was born in his mother's ancestral home named Kaavil near Panayannaarkavu, close to the town of Mannar in Central Travancore in 1869 (Malayalam year Kumbhom 27, 1044). His father was Mooloor Sankaran Vaidyar and mother was Veluthakunj Amma. Both his parents were from well educated, prosperous and  respected Ezhava families.
Padmanābhan was born in his mother's ancestral residence named Kaavil near Panayannaarkavu, close to the town of Mannar in Central Travancore in 1869 (Malayalam year Kumbhom 27, 1044). His father was Mooloor Sankaran Vaidyar and mother was Veluthakunj Amma. Both his parents were from well-educated, affluent, and esteemed Ezhava families.