William Herschel discovered NGC 5222 = H III-85 = h1638, along with NGC 5221 and NGC 5230, on 12 Apr 1784 (sweep 189). JH made three observations, describing NGC 5220 as "vF; S; R", "pB; S; R sbM; 30", and "vF; R; vglbM; 20".

400/500mm - 17.5" (5/30/92): faint, fairly small, elongated 4:3 SSW-NNE. A mag 15.5 star is at the south edge. A brighter mag 14.5 star lies 3' N. This is the slightly brighter galaxy of a pair with NGC 5221 5.4' N. Located 9.7' WNW of NGC 5230 in a group. A small companion just off the northeast edge was not seen.

600/800mm - 24" (6/1/13): moderately bright, fairly small, slightly elongated SSW-NNE, 30"x24", high surface brightness core, small halo. A mag 15.5 star is just off the south side, 0.6' from center. NGC 5221 lies 5.4' N and NGC 5230 is 9.6' ESE.

Notes by Steve Gottlieb