smokeless tobaccoBoston mayor Martin J. Walsh announced Wednesday a proposal to ban chewing tobacco, snuff and other tobacco products at Fenway Park and other professional and amateur sports venues in the city.

Mayor Walsh will officially file the ordinance with the City Council on Monday. If enacted, the ban would take effect April 1.

Walsh discussed the proposed ban at a city park, where he was joined public health officials and former Red Sox pitcher Curt Schilling.

“Our baseball parks are places for creating healthy futures, and this ordinance is about doing the right thing as a community for our young people,” Mayor Walsh said in a statement. “The consequences of smokeless tobacco are real, and we must do all that we can to set an example.”

Schilling announced last year that he had been treated for oral cancer, most likely caused by a 30-year chewing tobacco habit.

“I have seen cancer take the lives of people very important to me like my father, a lifelong smoker,” Schilling said in a statement. “If this law stops just one child from starting, it’s worth the price. Because that child could be yours, or mine.”

Although cigarette smoking has been on the decline in the U.S., the use of smokeless tobacco among youth has persisted. Nearly 15 percent of high school boys and almost 9 percent of all high school students reported using smokeless tobacco products in 2013, according to the Centers for Disease Control and Prevention.

In May, San Francisco — home of the 2014 World Series champion Giants — became the first U.S. city to ban chewing tobacco from all ballparks and playing fields. San Francisco will impose its ban starting Jan. 1.

The Boston ordinance would ban smokeless tobacco and any other tobacco product at sites for professional, collegiate, high school or organized amateur sporting events, including baseball, softball, football, basketball, soccer, and any other event involving a game or other athletic competition organized by a league or association.

Event organizers would be responsible for maintaining compliance with the ordinance. Signs would be posted at entrances, as well as dugouts, bullpens, training and locker rooms and press boxes. Violators would be fined $250 per offense.

“Boston’s action today sends a loud and powerful message that it’s time to break the harmful link between baseball and tobacco,” Matthew Myers, president of the Campaign for Tobacco-Free Kids, said in a statement. “Our national pastime should be about promoting a healthy and active lifestyle, not a deadly and addictive product.”