Police responded to Burke and K Streets in southeast Visalia for reports of a disturbance just before 2:00 a.m.
Police say the suspect's stepfather was able to pull the teen away from his mother.
The suspect ran from the scene before officers arrived but was later found and arrested.
He is booked for two counts of attempted murder.
The 2-year-old is at Valley Children's Hospital and is expected to be okay.
The Visalia PD Violent Crimes Unit is taking over the investigation.