Allegra Coleman was a fictional celebrity invented by writer Martha Sherrill for the purposes of a hoax magazine article.

In a parody of celebrity profiles, the article described Coleman's role in an upcoming movie with Woody Allen, her tempestuous relationship with David Schwimmer (including a scandal involving nude photographs taken by paparazzi), and her friendship with Deepak Chopra.

Within the context of the article, Coleman is already a successful actress, having appeared in the TV series Melrose Place, and the films Down Periscope, Guarding Tess and Cliffhanger, amongst others.

She is consistently portrayed in the article as flighty, irresponsible, and sweetly vacuous (Salon called her "brainless perfection"), but with a look and personal quality of "simple, irresistible vulgarity" that made her magnetically compelling.

Sherrill later wrote a satirical novel on Hollywood life that was essentially both an expansion and continuation of the original "Dream Girl" article, and featured Allegra Coleman as a prominent character.