The question asked for "towns", so avoiding names like Paris, France, the following are places with a population of less than 100,000 population:
Poughkeepsie, NY
Portland, ME
Palisades Park, NJ
Palo Alto, CA
Prescott, AZ
Portsmouth, OH
Portsmouth, RI
Plymouth, MA
Pawtucket, RI
Paris, TN
Panama City, FL
Piedmont, CA
There are no cities or towns in Canada beginning with the letter X.
Particle.
plans
pumpkin
PikePlaicePerchPiranha