The London-based human rights organisation's report - "Humanity Must Win" - called on both FIFA and host countries the US, Canada and Mexico to take urgent action to protect fans, players and other communities.
FIFA has promised a tournament where everyone "feels safe, included and free to exercise their rights".
But Amnesty said that pledge sits in "stark contrast" to conditions on the ground in all three host nations, especially the US, which hosts three-quarters of the 104 matches.
Amnesty described the US as facing a "human rights emergency" under the Trump administration, marked by mass deportations, arbitrary arrests and what it called "paramilitary-style" Immigration and Customs Enforcement (ICE) operations.
The acting director of ICE said last month the agency will be "a key part of the overall security apparatus for the World Cup".
This comes despite anger at the killing of two American citizens who were protesting aggressive ICE raids in Minneapolis in January.
'Pay the price'
Amnesty said none of the published host city plans address how fans or local communities will be protected from ICE operations.
Fans from four nations taking part this summer - Ivory Coast, Haiti, Iran and Senegal - face US travel bans and LGBTQ+ fan groups from England and across Europe have said they will not attend matches in the US, citing risks to transgender supporters in particular.
"This World Cup is very far from the 'medium risk' tournament that FIFA once judged it to be, and urgent efforts are needed to bridge the growing gap between the tournament's original promise and today's reality," the report said.
FIFA said earlier this month the 48-team tournament - the biggest World Cup in history - will proceed "as scheduled" with all teams taking part, despite uncertainty over Iran's presence due to the ongoing conflict in the Middle East.
The global football governing body, which has been heavily criticised over its decision to award a newly created "Peace Prize" to President Trump in December 2025, stands to earn $11 billion from the tournament cycle.
"While FIFA generates record revenues from the 2026 World Cup, fans, communities, players, journalists and workers cannot be made to pay the price," said Steve Cockburn, Amnesty's head of economic and social justice.
"It is these people - not governments, sponsors or FIFA - to whom football belongs, and their rights must be at the centre of the tournament."
The World Cup kicks off on June 11th at the Mexico City Stadium with the final scheduled for July 19th at the MetLife Stadium in New Jersey.