No, he was British...
and the OSS was an American outfit. However, he did have an OSS connection of sorts according to this source:
The "Fleming flair" also proved valuable in one other aspect: writing. As assistant to Admiral Godfrey, Fleming wrote countless memos and reports. His style and elegant arguments, plus his seemingly limitless knowledge of his subjects made the usual dry missives a pleasure to read. Eventually, Fleming wrote memos to William "Wild Bill" Donovan on how to set up the OSS, forerunner to the CIA. For that bit of work, Fleming received a revolver engraved with the thanks: "For Special Services."