"Clair" is a popular song by Irish singer Gilbert O'Sullivan and is one of his biggest-selling singles. Written by O'Sullivan and produced by Gordon Mills, it was the number one single in the UK Singles Chart for two weeks in November 1972, number one in Canada on the RPM 100 national singles chart the following January, and peaked at number two on the Billboard Hot 100 in the US. It was also O'Sullivan's second and last number one hit on the U.S. Easy Listening chart, after "Alone Again (Naturally)"
The song is the love song of an uncle for his young niece, though for the first part of the song, the ambiguous text leads one to think that it is from one adult to another. The brief instrumental introduction is the sound of O'Sullivan whistling, before he comes in. The real Clair was the young daughter of O'Sullivan's producer-manager, Gordon Mills, and his wife, the model Jo Waring. The little girl's giggling is heard at the end of this song. The "Uncle Ray" mentioned in the song is O'Sullivan himself, a reference to his real name of Raymond O'Sullivan. The instrumental break in the middle section is done half a step up from A to B-Flat, before going back to A.