An organic light-emitting device includes: a first electrode; a second electrode; and an organic layer between the first electrode and the second electrode, the organic layer including an emission layer, wherein the emission layer includes a first host and a dopant, the first host is represented by one selected from Formulae 1 and 2, and the dopant is represented by Formula 7:
Ar
11
(L
11
)
a11
-(R
11
)
b11
]
n11
Formula 1
Ar
21
(L
21
)
a21
-(R
21
)
b21
]
n21
Formula 2
M(L
1
)
n71
(L
2
)
n72
. Formula 7
The organic light-emitting device may have high efficiency and long lifespan and may show little change in the efficiency at an x-coordinate (CIEx) value of 0.21.