Margaret attended Illinois Wesleyan University and then spent two years at Hart Conway's Dramatic School in Chicago where she won the Joseph Jefferson diamond medal for excellence in Shakespearean plays.
With strong letters of recommendation Margaret went to New York where Daniel Frohman, the first producer to whom she applied, engaged her at once. He did not like her name, Maud Ellen Light, and changed it to Margaret Illington, which he coined from the state and town of her birth.
She first appeared at the Criterion Theatre, September 3, 1900, as the gypsy girl Michel supporting James K. Hackett in The Pride of Jennico. In 1902 she played Victorine in Frocks and Frills at Daly's and also Fleur-de-Lys in Notre Dame. She then went to Richmond, Virginia, as leading woman in a stock company and later played with E. H. Sothern in If I Were King.
On November 19, 1903, she made an instantaneous success as Yuki in A Japanese Nightingale at Daly's. In March 1904 she played Henriette in the "all-star" production of The Two Orphans at the New Amsterdam Theatre. Thereafter she appeared in the current plays of the day. She played Shirley Rossmore in The Lion and the Mouse in the United States.
On May 22, 1906, Margaret made her first appearance in London in the same part at the Duke of York's Theatre. After fourteen months the strain of the part was too great for her and she collapsed on the stage of the Park Theatre, Boston, in October 1908. In 1910 she appeared in The Whirlwind and the following year played Maggie Schultz in Kindling. Later she played in Within the Law, The Lie, and The Gay Lord Quex. In 1917 she made her only motion picture, playing in Sacrifice. Her last appearance was as Ruth Brant, in A Good Bad Woman, in 1919. After touring in the play she retired in the same year.
She died at Miami Beach, Florida.
Margaret Illington was a woman of strong personality and great magnetism. Her acting had a vibrant emotional quality which in great moments stirred and aroused an audience. Hence she was at her best in strong parts.
On November 22, 1903, Margaret married Daniel Frohman. On November 14, 1909, a few days after the divorce had been granted, she was married to Maj. Edward J. Bowes, who from that time managed her stage career.