It is legal to distribute flyers, but cities and local governments are allowed to have laws that govern their distribution, according to FindLaw. Flyers cannot be outlawed because this would interfere with rights to free speech provided by the First Amendment.
Common regulations concerning flyer distribution dictate where they may be posted and how they can be posted. For example, some cities only permit flyers to be posted on utility poles, while others specifically prohibit this. Flyer distribution is often regulated to prevent the flyers from becoming eyesores and turning into litter. They generally cannot be posted on someone's private property unless the owner has given express permission.