The 22-year-old's death on 16 September sparked one of the largest - and most significant - waves of dissent to shake the Islamic Republic in years.
Security forces in Iran have prepared themselves well for the first anniversary of Mahsa Amini's death.
In major cities, police checkpoints littered the streets and military units were sent to restive areas of the country, while scores of people were arrested.
The young Kurdish woman died on 16 September 2022 in the custody of the Iranian morality police (known as Irshad Patrol), sparking major nationwide protests.
One year on, the political and social effects of her death still ripple through Iran.
Several hundred demonstrators were killed and more than 20,000 people were arrested during the protests that lasted several months. They are known as the "Woman Life Freedom" movement, reflecting the slogan used by those opposed to the Islamic Republic.
Dozens of the regime's security forces and its infamous Basij force were also killed and injured during the unrest.
But what impact have the protests had on Iran?
Resistance to compulsory hijab has become a sign of protest
In Iran, women must cover their hair with a headscarf by law.
Even before last year's protest movement, Iranian women would commonly be seen wearing it loosely around their heads or at times their shoulders in defiance of the rules, which are deeply unpopular among large parts of the population.
Disputes over the mandatory hijab have become one of the main issues hitting the headlines inside Iran.
Without officially announcing their decision, Iranian authorities withdrew the morality police - who enforce the country's strict Islamic dress codes and rules - from the streets in the weeks and months following Amini's death.
Violence perpetrated by the morality police towards women and girls is widely cited as one of the main factors leading up to the dissent.
Now Iranian officials are trying to find a way to deal with the growing number of women who are refusing to cover their hair.
Yet, the balance of power between the regime and defiant women may have changed.
Although the authorities have stressed several times in recent months that those breaking the rules will be punished, observers say the current situation is vastly different from what women faced before Amini's death.
Before the protests, Iranian officials were concerned mainly with women wearing what they called "bad hijab" - not wearing it in a way that covers the hair completely - whereas nowadays they see more and more women without a headscarf in public.
Amini herself was arrested by the morality police for alleged "bad hijab", while travelling with her family to the capital, Tehran. She reportedly was badly beaten, suffering several violent blows to the head, though Iran's authorities deny this.
Morality police have returned to the streets to resume their patrols, with women seen unveiled in their cars sent warnings over SMS. However, these officers are no longer presenting themselves as "morality police" as they used to before Amini's death.
A Euronews report in April found China was "turbocharging" this crackdown on Iranian women, providing crucial technologies and other support to Iran's government.
Ali Khamenei, the leader of the Islamic Republic, a few months ago spoke about the acceptance of "weak hijab", as he called it.
His comments could be interpreted as a sign that the Iranian authorities now prioritise dealing with women who refuse to cover up at all.
Still, many ordinary Iranians are more concerned about skyrocketing prices and the country's sanctions-racked economy.
A recent measure taken by Iranian authorities to confront and punish rule breakers is the so-called "Chastity and Hijab" bill, which empowers intelligence agencies and the police to take action against women.
United Nations experts have labelled the legal changes, which create new penalties and heavy fines for unveiled women, "gender apartheid".
A growing appetite for 'regime change'
Sparked by Amini's death, protests have morphed into one of the most significant challenges to Iran's theocratic rulers in years.
Unrest was eventually crushed amid a wave of violence and bloodshed, with the security forces shooting people for honking their cars in support of demonstrators and using military-grade weapons in Iranian Kurdistan.
But protests continue in Sistan and Baluchistan, with weekly demos in the latter's capital Zahedan persisting long after relative calm returned elsewhere in the country.
The nationwide protests in 2022 were not only one of the most serious challenges to the regime since the 1979 Islamic revolution, they were also unprecedented in terms of geographical spread and length.
Experts suggested to Euronews in November that the society was uniquely united, with Iranian human rights lawyer Shadi Sadr saying at the time that the unrest showed the regime had lost approval among its "core supporters".
Iranian authorities - caught off guard by the dissent - are now ultra-sensitive towards a possible return of trouble on the streets.
The arrest of relatives of killed protestors ahead of the Amini anniversary has been interpreted by some as a sign of the regime's insecurity.
Disagreements inside the regime about how to deal with resistance have also been reported in recent months, with Cornelius Adebahr, a non-resident fellow at the Carnegie Europe research centre, pointing to possible "power struggles" among elites back in December.
Besides "woman, life, freedom", many protesters chanted slogans openly calling for regime change.
Previous leaders in Iran, such as former president Hassan Rouhani, have tried to reform the Islamic Republic from the inside, relaxing social restrictions. But the protests underscored that many Iranians, especially the young, want a complete change of system.
Iranians are facing an economic crisis mainly due to international sanctions over the country's nuclear programme.
Households up and down the country are challenged by rapid and consecutive waves of price increases, with the Iranian currency losing more than 90% of its value over a decade, according to The Economist.
The authorities are worried about the possible convergence of public protests against dire economic conditions, like those that erupted in 2019 due to fuel price rises, with unrest similar to that after Amini's death.
An uneasy status quo between the regime and protestors has settled in but the current situation seems unstable, tense and fragile in many ways.
Any incident in the coming weeks and months could possibly break the balance of power in one way or another. Any unknowable event, like the death of Amini, could "surprise" political observers.
In the meantime, one of the main uncertainties for the regime is who will take over from the 84-year-old supreme leader.
Ali Khamenei has led the Islamic Republic for more than three-quarters of its tumultuous history. He is the final decision-maker in the country, especially on matters related to security and foreign policy.
Owing to the importance of his role and position, some say that it is difficult to believe Iran and its military-security complex will not change in his absence.