Mendoza, 42, was standing outside the sporting complex in Cuernavaca, Mexico with other parents when two armed men arrived on a motorbike.
One of the men stepped off the motorbike and shot the mum multiple times before escaping with his accomplice, according to Mexican news outlets.
Paramedics and police rushed to the scene on Tuesday evening, where Mendoza was pronounced dead.
The actress rose to fame following a lead role in the 2005 film La Mera Reyna del Sur.
She also appeared in a number of soap operas, but in recent years was dedicated to her career as a singer, and recorded five albums.
It is not yet clear who was behind Mendoza’s murder, or any possible motive.
Cops have carried out a search for the suspects, but no one has been arrested.
Mendoza was the victim of a brutal kidnapping in 2010, when she was snatched with her husband and six-month-old son from the couple’s car wash business.
They were taken to a safehouse where they were beaten before eventually being released hours later by three masked captors.
Several days later, the kidnappers called Mendoza to extort her and demand that she move from the state of Morelos.
Since the horror kidnapping, Mendoza had reportedly complained to the Morelos State Attorney General’s Office on several occasions about receiving death threats.
At least 10 women were murdered in Mexico every day last year, according to official data.
Amnesty International said around a third of victims – 940 – were cases of femicide, or the intentional murder of women because of their gender – calling it a “shocking epidemic”.
A recent United Nations report on gender violence found Mexico was the second most dangerous country in the world for women.
The Attorney General’s Office said Mendoza’s killing would be investigated as femicide, according to Efe news agency.
