The ads are part of the Mayors Against Illegal Guns coalition and coincides with Thursday's National Day to Demand Action.
"We need to remember the 26 victims who lost their lives. She just wanted to teach little kids. That was her goal and she died doing it," the ad proclaims.
New York mayor Michael Bloomberg spent $12 million to target lawmakers to support expanded gun control.
San Francisco Mayor Ed Lee and Oakland Mayor Jean Quan are also part of the coalition.
