The infant had been missing from her house in Rishi Palace Colony area here since January 19 when her aunt had gone away.
The body was recovered from the well by fire brigade officials and has been sent for postmortem, they said.
Meanwhile, the baby's parents and angry residents of the area today staged a demonstration at the Futi-Kordi circle demanding arrest of the culprit in the case, police said.
They blocked six adjoining roads in Chandan Nagar area during the demonstration.