Shatner, best known for his role as Captain Kirk in Star Trek, is to serve as Grand Marshall.
It is not clear if Shatner, who is an experienced horseman, will lead the parade on horseback or ride in a wagon or antique car.
Shatner, who is 83, says he has been to Calgary before, but never to the Calgary Stampede.
The Calgary Stampede runs from July 4 to 13.
The parade gets underway at 9:00 a.m. on July 4.
"Leading the parade will be quite a way to experience my first time,” Shatner said in a release Tuesday.
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