Designed by renowned architects Benno Janssen, and Franklin Abbott, the hotel was the last building venture of Henry Clay Frick, one of Pittsburgh’s wealthiest industrialists, and completed at a cost of $6 million. Frick envisioned the William Penn as Pittsburgh’s showplace, designed to rival the great hotels of Europe in Old World style and enhanced with the sophisticated technology offered by the 20th century.

The initial phase of the hotel included 1,000 guest rooms, and an elegant two-tier Grand Ballroom located on the 17th floor. In 1928, construction of the Grant Street Annex addition commenced. Completed in 1929, it added an additional 600 guest rooms as well as the crowning jewel, the Urban Room, designed by Joseph Urban, a set designer for the Ziegfeld Follies. With this addition, the William Penn became the largest hotel between Pittsburgh and Chicago, and a major convention facility for Pittsburgh.

Omni William Penn Hotel is also a member of Historic Hotels Worldwide, which is dedicated to promoting heritage and cultural travel to prestigious historic treasures.