Dr Charlie Main, senior project manager for the Shiant Isles Recovery Project, said: "This is an absolutely fantastic moment for the Shiant Isles and everyone involved in the project is delighted that they are now officially rat free.
"With so many of Scotland's seabird populations in decline it's vital that we do all we can to help them.
"Making these islands a secure place for them to breed is really important."
Dr Main said it was hoped numbers of seabirds would recover over the next few years.