Penelope Van Dyke Johnson was born on October 27, 1886, in Chattanooga, Tennessee to James Whiteside and Sue Coffin (Cleague) Johnson. After graduating from Chattanooga High School in 1904, she attended Western College in Oxford, Ohio. On February 17, 1909, she married Samuel Boyd Allen of Knoxville, Tennessee, and on July 31, 1911, the couple's daughter, Penelope Van Dyke Allen, arrived.

Allen enjoyed many different careers, including society editor, advertising salesman, political writer, and sports reporter for the Chattanooga News from 1919-1923. She actively campaigned for woman's suffrage and in 1922 narrowly lost a seat in the Tennessee State Legislature. In 1923, she began work as a traveling advertising agent of the Chattanooga Medicine Company. From 1933-1937, Allen wrote the Chattanooga Times Magazine's feature Leaves from the Family Tree, which she published as a book in 1982.

During the 1920s, Allen became state historian for the Daughters of the American Revolution in Tennessee, and in the 1930s, she directed the gathering of local records for the Works Progress Administration. As an authority on the Cherokee Indians, she developed a large collection of Cherokee books, manuscripts, letters, and other documents, and published several articles and the book History of the Cherokee Indians. Allen wrote several other books, including Historic Chattanooga, A Guide Book, and Tennessee Soldiers in the Revolution.

Penelope Johnson Allen died on January 9, 1985 in Chattanooga, Tennessee