The extensive search kicked off at around 2.45am in sub zero temperatures after the alarm was raised at the Ripon care home on Kearsley Road.
North Yorkshire Police's Force Control room co-ordinated the emergency search undertaken by Response team officers, the dog unit and a police helicopter and covered nearby fields and locations across the Ripon area.
The 74-year-old man was located almost two hours later, but safe and well, by officers on the bridge on North Road, near Little Studley, at 4am. He had been walking along the river bank.
A police spokesperson said he was returned back to the care home.