The organisation appealed to its friends around the world to help put pressure on Israeli Prime Minister Benjamin Netanyahu to release Tamimi without delay.
"There is nothing Ahed Tamimi has done that can justify the continuing detention of a 16-year-old child. She is one of approximately 350 Palestinian children held in Israeli prisons and detention centres" it said.
The rights group said Tamimi – who is now referred to as the "Rosa Parks of Palestine" – has been bravely fighting the Israeli occupation yet may face up to 10 years in jail because of an argument with Israeli soldiers.
On 15 December Ahed and her family protested the US President Donald Trump's recognition of Jerusalem as the capital of Israel when an Israeli soldier shot her 14-year-old cousin, Muhammad, in the head at a close range.
The shot required dangerous surgery which involved removing part of the boy's skull in order to take out the rubber bullet.
Later that day Ahed confronted Israeli soldiers when they entered the yard of her family's house. A video, which has since gone viral, shows the unarmed girl slapping, shoving and kicking the armed Israeli soldiers who were wearing protective clothing.
"It was clear that she posed no real threat to them because they easily removed her, but now she could face up to 10 years in prison, which is a grossly disproportionate punishment" the organisation said.
On 19 December Ahed's home was raided by Israeli soldiers during the night. She was arrested and now faces charges of aggravated assault, obstructing the work of soldiers, and incitement.
Amnesty said that while in detention Ahed has suffered aggressive interrogations, sometimes at night, whilst her family has been threatened.
"Her trial before an Israeli military juvenile court is imminent, we must mobilise quickly and effectively," the rights group said.
The organisation demanded the release of Ahed and that Palestinian children are not detained or imprisoned "except in cases where it is demonstrably necessary and proportionate as a last resort for the shortest appropriate period of time".