She was born Frances McCann on February 2, 1903 in Brooklyn, New York. Her parents, Thomas and Mary McCann, had both been born in Ireland. After graduating from high school Iris briefly attended secretarial college. The beautiful brunette dropped out to become an artist's model. Soon she started appearing in advertisements and on magazines covers. Iris became known as "the girl with a million faces". In an interview she said "To be a model is pleasant enough but it isn't any good for a girl who is ambitious" B.P. Schulberg offered her a long term contract at Paramount in the Summer of 1926. She made her film debut in the drama Stranded In Paris.
Then she appeared in Children Of Divorce with Clara Bow. Her performances got good reviews and her future seemed bright. Iris was chosen to be one of the 1927 WAMPAS Baby Stars along with Helene Costello and Sally Rand. Unfortunately in February of 1927 she came down with tuberculosis and had to be hospitalized. She wanted to continue acting but her health was too fragile. Her final film was the comedy Wedding Bills. Iris married publisher Bert MacKinnon on January 3, 1928. The couple moved to Mt. Vernon, New York and she settled into her new life as a housewife. Tragically in 1936 her tuberculosis returned. She passed away on December 21, 1936 at the young age of thirty-three. Iris was buried at Gate of Heaven Cemetery in Hawthorne, New York.
