Jill Colleen Hennessy, daughter of Jim and Marci Hennessy of Chesterfield, and Joseph Allen Mathieu, son of Allen and Susie Mathieu of Glendale, have announced their engagement.

She is the granddaughter of Gerald and Margaret Hennessy of Balllwin and Harriet and the late Joseph Harris of Maryland Heights.

He is the grandson of Louis J. and Rosemary Doerr of Creve Coeur and the late Milton and the late Arneida Mathieu of Thief River Falls, Minn.

The bride-to-be is a graduate of Parkway Central High School and the University of Missouri-Columbia, where she earned a bachelor of journalism degree. She is currently an account executive at Yellow Dog Productions, L.L.C.

Her fiancé is a graduate of DeSmet High School and Loyola University-Chicago, where he earned a bachelor of science degree in psychology. He is currently a medical sales representative.

A September, 2011 wedding is planned.