The Ardmore man will continue to play club hurling but cited family and work commitments for his decision to call it a day on his inter-county career.
Hennessy made his senior championship debut in the 2005 All-Ireland quarter-final defeat to Cork.
He won a national league title when Waterford defeated Kilkenny in the final in 2007 and followed up with a Munster title in July of the same year after Waterford’s win over Limerick in the final. (3-17 to 1-14).
Hennessy picked up his second Munster title in 2010 when Waterford saw off the challenge of Cork by three points in a replay after the final finished 2-15 apiece.
Announcing his decision Hennessy said he had his mind made up for some.
“I’ve had my mind made up for a good while and I was going to leave it later but I didn’t want people to think that I was calling it a day because of the new manager”.
Hennessy’s retirement is the second high-profile recent departure from the Waterford squad following long-serving defender Eoin Murphy’s decision to call time on his inter-county involvement last week.
