It comes just weeks after Katie posted a touching message on social media following her father's death saying "Words cant express the solace our family's received from all the love & support during this trying time".
The document states that David had approximately $150,000 in various assets and the ownership of the assets should be handed over to Beau.
Katie Cassidy was raised by her mother and her stepfather, Richard Benedon.
The majority of it has been inherited by son Beau, a 26-year-old singer-songwriter.
In the will, which was filed in 2004 and obtained this week by the Blast, the "Partridge Family" star wrote: "It is my specific intent not to provide any benefits hereunder to Katherine Evelyn Cassidy and/or any descendant of Katherine Evelyn Cassidy".
"I've never had a relationship with her".
Cassidy passed away in November aged 67 after suffering organ failure in relation to his dementia.
"She has a completely different life", he told the magazine.
Still, when news of David's deteriorating health broke, Katie rushed to be at her father's bedside - leaving a fan convention for her TV show "Arrow" early in order to be with him. He said he and his daughter weren't in contact, but he said he was proud of her (she's an actress). Cassidy's three half-siblings will get anything that is considered "music memorabilia".
Despite this, the two had a relationship and she was among those by his hospital bed when he died, tweeting days later, "My father's last words were "So much wasted time". Originally it named his then-wife Susan as personal representative, but the role fell to his cousin following their 2016 divorce. "[But] I'm proud of her".
As of late, Katie has not yet commented regarding her dad's decision to leave her out of his will.
According to The Blast, there was no funeral, although his loved ones are planning to hold a private memorial service after the festive holidays. Katie and Cassidy were last pictured together at a red carpet event in 2007.