"[1] Cash Box called the song a "driving Eric Carmen composition that is destined to become the group's fourth successive chart item.

"[6] Allmusic critic Mark Deming said that "the king-sized guitar figure Wally Bryson uses to launch ['Tonight'] has a bark worthy of Jimmy Page, while drummer Jim Bonfanti lets loose with lots of manic drum fills worthy of his obvious role model, Keith Moon.

"[7] Music journalist Ken Sharp called it "the quintessential Raspberries song" and "the perfect power pop song", noting an influence from the Small Faces and praising "Carmen's deliciously gritty Steve Marriott-like vocal, Wally Bryson's ripping power chords, Dave Smalley's pulsating bass line and Jim Bonfanti's powerhouse drumming.

"[8] Ultimate Classic Rock critic Dave Swanson rated it as the Raspberries 4th best song, calling it "pop perfection in three and a half minutes of glory" and claiming it has "one of the best drum exclamation point endings ever.

[10] Country musician Bill Lloyd rated "Tonight" as the 5th greatest power pop song of all time, saying that "this was the recording where [the Raspberries] got the balance just perfect.