Chairman Sir Anthony Bamford gifted the two 3CX backhoe loaders in response to an appeal from relief agencies for foreign aid.
The machines will be managed by the US government, which is coordinating the relief effort on the Caribbean island which was hit by an earthquake measuring 7.0 on the Richter scale last week (12 January).
Bamford said: "The scale of the devastation is unimaginable and it’s heart-rending to see the human suffering caused by the disaster. There is clearly a lack of equipment on the island and I hope our gift of JCB machines will help in some small way to alleviate that suffering and in the rebuilding in the aftermath of the earthquake."
The company has a history of donating equipment in the wake of natural disasters.
It sent six machines to Sichuan, China, in the wake of the earthquake that devastated the region in 2008. Equipment worth more than £1m was also donated to help victims of the Asian Tsunami in 2004.
Subscribe to Horticulture Week for more news, more in-depth features and more technical and market info.