Michigan State Police reported an active shooting incident about 12.30pm at Temple Israel Synagogue in the Detroit suburb of West Bloomfield.
Few official details were immediately available but aerial news footage showed plumes of smoke rising from the roof of the building.
Large numbers of police and fire department vehicles converged on the scene.
Oakland County Sheriff Michael Bouchard told CNN that there were no confirmed injuries, "except potentially the shooter".
Bouchard told reporters the suspect breached the building, driving through the doors with a vehicle, and drove down the hall before being confronted by security.
Police could not say what killed the suspect at this point, adding that security did exchange gunfire with him.
No children or staff were injured, and one lead security person was hit by the car and taken to the hospital for treatment, he said.
"That individual should be okay," Bouchard said.
A law enforcement official familiar with the matter later told Reuters the suspect was shot dead at the scene.
CNN, citing multiple law enforcement sources, said a large amount of explosives was found in the back of the suspect's car.
Temple Israel, which has more than 12,000 members, runs an early-childhood centre that provides childcare and education to children as young as six weeks old, according to its website.
Local news media reported that children from the daycare centre, some of whom had escaped to nearby homes, were being ushered away from the synagogue on buses to be reunited with their parents.
FBI Director Kash Patel wrote on X: "FBI personnel are on the scene with partners in Michigan and responding to the apparent vehicle ramming and active shooter situation out of Temple Israel Synagogue in West Bloomfield Township, Michigan."
The Jewish Federation of Detroit posted a message on its Facebook page saying its affiliated agencies were "currently in precautionary lockdown" in response to the Temple Israel incident.
Jewish organisations throughout the United States have been operating under heightened security since US and Israeli forces launched air strikes on Iran on February 28, sparking an intensifying war across the Middle East.
"We've been talking for two weeks about the potential, sadly, of this happening. So there was no lack of preparation," Bouchard said on CNN.
"All Jewish facilities in the area are going to have a lot of extra presence around it until we figure this out."
"Antisemitism has no place in Michigan and cannot be tolerated," Michigan Attorney General Dana Nessel said in a statement.
"In moments like these, it's more important than ever that we come together, stand with our neighbours, confront hate whenever it appears and build stronger communities."
