Oxfam is opposed to all trade from Israeli settlements.
The 29-year-old actress released a statement saying she and Oxfam had a fundamental difference of opinion over the issue.
"Scarlett Johansson has respectfully decided to end her ambassador role with Oxfam after eight years," the statement said.
"She and Oxfam have a fundamental difference of opinion in regards to the boycott, divestment and sanctions movement. She is very proud of her accomplishments and fundraising efforts during her tenure with Oxfam."
More From This Section
The charity organisation, in a release, said they were proud of their relationship with Johansson who has worked with them since 2005 and as its ambassador travelled to countries like India, Sri Lanka and Kenya.
The organisation accepted that they were discussing the matter with Johnasson.
"Oxfam believes that businesses that operate in settlements further the ongoing poverty and denial of rights of the Palestinian communities that we work to support. Oxfam is opposed to all trade from Israeli settlements, which are illegal under international law.