The 2019 Open Champion has been sponsored by the Cavan company since 2017.
Shane Lowry has ended his relationship with Kingspan.
The move from the Offaly golfer comes following a recent report that branded the building products company as "dishonest" for their role in the Grenfell fire disaster of 2017 that saw 72 people lose their lives.
The report found that the County Cavan based company created 'a false market' in insulation for use in buildings over 18 metres in height.
The company's K15 insulation product made up approximately 5% of the insulation in the tower block and was used without the company's knowledge.
The primary reason for the spread of the fire was cladding, which was not made by Kingspan.
Following its publication, Kingspan acknowledged the "wholly unacceptable historical failings that occurred in part of our UK insulation business."
Lowry has been sponsored by the Cavan company since May 2017, one month before the disaster.
In a statement, the Clara man says both sides have "mutually agreed to discontinue our sponsorship relationship" which they believe is the "right decision for all concerned".