The eastbound CP train derailed about 2 p.m. in Watertown in the southeastern part of the state. The railroad said at least 10 cars derailed, and some were leaking.
No fires or injuries were reported. CP was sending teams to the site.
"CP takes this incident extremely seriously," the railroad said in a news release.
On Saturday, a freight train derailed near Alma in western Wisconsin, spilling thousands of gallons of ethanol. BNSF Railway said crews continued Sunday to transfer ethanol from the derailed cars and get the cars back on the tracks.
The BNSF train derailed at 8:45 a.m. Saturday about two miles north of Alma, a town along the Mississippi River. Some of the 25 derailed cars were empty auto racks and tanker cars.
BNSF said railroad crews stopped the leaks from five tanker cars and placed containment booms along the shoreline. One tanker released an estimated 18,000 gallons of ethanol, and the other four released an estimated 5 to 500 gallons each.
No one was hurt. BNSF said it expects the tracks to return to service Monday morning.
Comment: All these train accidents are beginning to look suspicious: Another Buffett-owned oil tanker train derails in Wisconsin one day after Obama kills Keystone XL pipeline