A new and distinct cultivar of Paeonia plant named ‘Smith Opus 1’, characterized by its compact and symmetrically globular plant habit; vigorous growth habit; relatively narrow and finely-incised leaves; numerous large flowers that are arranged on strong peduncles above and beyond the foliar plane; long flowering period; developing flowers are yellow in color and flushed with pink imparting a light orange color to the opening flowers; fully opened flowers are yellow in color and have large prominent red-colored flares at the petal bases; and good garden performance.