The girl was brought to shore safely by members of the Hornsea Inshore Rescue crew on Sunday afternoon, and a member of her family also got into difficulty after trying to swim out to her.
She had been playing on the beach at Hornsea when she was blown half a mile out to sea.
Inflatable toys are designed for use in swimming pools and should never be taken in the sea.
The Spirit of Hornsea vessel operated by the charity responded to a distress call within seven minutes of the alarm being raised.
The girl was described as 'cold, afraid but unharmed' when she was found. Her relative returned to the beach without requiring assistance.
Hornsea Inshore Rescue coxswain Steve Hall said: “Fortunately we were very quickly on the scene as the incident had been spotted and reported by Hornsea Coastwatch who had then called the Coastguard who in turn tasked Hornsea Inshore Rescue.
"Our crew then ensured a very quick launch and we were able to rescue the casualty. It once again emphasises the danger of using inflatable toys, airbeds etc in the sea. An offshore breeze can so quickly have them well out to sea in no time and a tragedy could then happen.”
The girl was met at the lifeboat station by her family, who thanked the crew for saving her life.
The volunteers involved were Steve Hall, Adam Collins, Jake Roberts, Andy Wilson and launch master Craig Beadle.
The Hornsea Inshore Rescue boat is funded by charitable donations. A group of local volunteers took over the running of the lifeboat when the Coastguard pulled its crew out of Hornsea in the early 1990s, leaving the town unmanned.
Donations to the HIR charity can be made via their Justgiving page.