Cheptegei's body was transported on Friday from Kenya to Uganda, where the 33-year-old athlete will be buried in her family's village of Bukwo.
Rebecca Cheptegei was a sergeant in the Ugandan army and will be buried with military honors. A number of athletes will participate in the ceremony, including Alex Malinga, who previously trained Cheptegei and also competed for Uganda in the Olympic Games.
She contributed strongly to promoting sports, says Malinga to AFP.
Bessie Modest Ajilong, the local president's representative at the funeral, says that Cheptegei was a "heroine".
The murder has caused outrage in the region and shed light on what activists describe as an epidemic of murders of women in the region. In Kenya, 725 murders of women were reported in 2022, according to UN figures.
At least two other female athletes, Agnes Tirop and Damaris Mutua, have fallen victim to domestic violence since 2021.
Rebecca Cheptegei was attacked by her boyfriend in her home in Trans Nozia, Kenya, near the border with Uganda. According to local media, her daughters witnessed the attack.
According to Cheptegei's family, the marathon runner and her boyfriend had been in conflict over the ownership of the property where Cheptegei lived.
The boyfriend was seriously injured in the attack and later died of his injuries, according to Kenya Star.