Reem Saleh Riyashi (Arabic: ريم صالح الرياشي Rīm Ṣāliḥ ar-Riyāshī; 1981 – 14 January 2004) was a Palestinian suicide bomber from Gaza City who killed herself and four Israelis at the Erez crossing on 14 January 2004. Hamas and Al-Aqsa Martyrs' Brigades claimed that the attack by Riyashi was a joint operation mounted as a response to weeks of Israeli incursions into West Bank cities that had left about 25 Palestinians dead.

Reem Riyashi was born in 1981. Unlike most bombers, Riyashi came from a wealthy family. She was the eighth Palestinian female suicide bomber, but only the second to have left behind children. Riyashi was the first female suicide bomber sent by Hamas whose spiritual leader at the time, Ahmed Yassin had initially objected to the involvement of women in such actions, altering this position shortly before his assassination by the Israel Defense Forces in March 2004. After having two children, Riyashi recorded a message, during which she expressed her dreamed of being the first woman turning "my body into deadly shrapnel against the Zionists" since she was 13. She added that, while she did love her children, her love to see God was stronger.

On 14 January 2004, Riyashi detonated a 2 kg bomb inside a building where the thousands of Palestinians who cross each day from Gaza to work in a neighbouring industrial zone are processed. The Israeli army reported that when she reached the metal detector at the terminal, Riyashi pretended to be disabled and claimed to have metal plates in her leg which would sound the alarm. She asked to have a body search instead. After being taken to an area where a group of soldiers and policemen were checking bags, she was told to wait for a woman to come and search her in a cubicle. It was then that she detonated the explosive device.

Two Israeli soldiers, a policeman and a civilian security worker were killed. Seven other Israelis and four Palestinians were injured.

A traditional memorial tent was immediately set up by her family near her home in Gaza City. Riyashi's relatives had no explanation for why a mother with children so young would choose to become a suicide bomber. At the time of Riyashi's death, her son Obeida was three years old, and her daughter Doha 18 months old. Her brother-in-law, Yusuf Awad, denounced the attack, adding that "we don't accept women doing such things."

Criticism of the operation in the Palestinian press was unprecedented. Hamas received widespread criticism from among Palestinians and some supporters for deploying a young mother as a suicide bomber and for publishing photographs of Riyashi posing with her children and weapons. In one photograph, Riyashi's son is clutching what appears to be a mortar shell and is wearing a Hamas headband while another picture shows Riyashi gazing at her children.

Hani Almasri, a Palestinian journalist at Al-Ayyam, told the Associated Press that Hamas' decision to release the photographs damaged the Palestinian cause and that Hamas would gain little advantage by these actions since in his opinion, there was less support from among the Palestinian people for military operations than had been the case previously.

Hamas defended its decision to release the photographs stating that the pictures revealed the depth of the despair of Palestinian women and the depth of their desire to defeat the occupation. Sheikh Ahmad Yassin said that Riyashi's example would inspire more women to die in the fight against Israel, urging more to volunteer.