A condensed cyclic compound represented by Formula 1A-2: wherein, in Formula 1A-2, X 11 is S or O; X 21 is S or O; L 1 to L 3 and L 21 are each independently one of Formulae 2-1 to 2-34: wherein, in Formulae 2-1 to 2-34, Y 1 is O, S, C(Z 3)(Z 4), N(Z 5), or Si(Z 6)(Z 7); Z 1 to Z 7 are each independently selected from, a hydrogen, a deuterium, -F, -Cl, -Br, -I, a cyano group, a C 1 -C 20 alkyl group, a C 1 -C 20 alkoxy group, a phenyl group, a naphthyl group, an anthracenyl group, a triphenylenyl group, a pyrenyl group, a phenanthrenyl group, a fluorenyl group, a chrysenyl group, a carbazolyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a pyridinyl group, a pyrimidinyl group, a triazinyl group, a quinolinyl group, an isoquinolinyl group, a quinazolinyl group, a quinoxalinyl group, and a biphenyl group; d1 is an integer selected from 1 to 4; d2 is an integer selected from 1 to 3; d3 is an integer selected from 1 to 6; d4 is an integer selected from 1 to 8; d5 is an integer of 1 or 2; d6 is an integer selected from 1 to 5; and * and *' each indicates a binding site to a neighboring atom, a1 to a3, and a21 are each independently an integer selected from 0 to 5; R 1 to R 7, and R 21 are each independently selected from a hydrogen, a deuterium, -F, -Cl, -Br, -I, a cyano group, a C 1 -C 20 alkyl group, a C 1 -C 20 alkoxy group, and one of Formulae 4-1 to 4-31: In Formulae 4-1 to 4-31, Y 31 is O, S, C(Z 33)(Z 34), N(Z 35), or Si(Z 36)(Z 37); wherein Z 31 to Z 37 are each independently selected from a hydrogen, a deuterium, -F, -Cl, -Br, -I, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid or a salt thereof, a sulfonic acid or a salt thereof, a phosphoric acid or a salt thereof, a C 1 -C 20 alkyl group, a C 1 -C 20 alkoxy group, a phenyl group, a naphthyl group, an anthracenyl group, a pyrenyl group, a phenanthrenyl group, a fluorenyl group, a chrysenyl group, a carbazolyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a pyridinyl group, a pyrimidinyl group, a triazinyl group, a quinolinyl group, an isoquinolinyl group, a quinazolinyl group, and a quinoxalinyl group; e1 is an integer selected from 1 to 5, e2 is an integer selected from 1 to 7, e3 is an integer selected from 1 to 3, e4 is an integer selected from 1 to 4, e5 is an integer of 1 or 2, e6 is an integer selected from 1 to 6, and * indicates a binding site with a neighboring atom, b1 to b3, and b21 are each independently an integer selected from 1 to 5; c1 is an integer selected from 1 to 4; and c2 is an integer selected from 1 to 4. X 11 is S or O; X 21 is S or O; L 1 to L 3 and L 21 are each independently one of Formulae 2-1 to 2-34: wherein, in Formulae 2-1 to 2-34, Y 1 is O, S, C(Z 3)(Z 4), N(Z 5), or Si(Z 6)(Z 7); Z 1 to Z 7 are each independently selected from, a hydrogen, a deuterium, -F, -Cl, -Br, -I, a cyano group, a C 1 -C 20 alkyl group, a C 1 -C 20 alkoxy group, a phenyl group, a naphthyl group, an anthracenyl group, a triphenylenyl group, a pyrenyl group, a phenanthrenyl group, a fluorenyl group, a chrysenyl group, a carbazolyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a pyridinyl group, a pyrimidinyl group, a triazinyl group, a quinolinyl group, an isoquinolinyl group, a quinazolinyl group, a quinoxalinyl group, and a biphenyl group; d1 is an integer selected from 1 to 4; d2 is an integer selected from 1 to 3; d3 is an integer selected from 1 to 6; d4 is an integer selected from 1 to 8; d5 is an integer of 1 or 2; d6 is an integer selected from 1 to 5; and * and *' each indicates a binding site to a neighboring atom, a1 to a3, and a21 are each independently an integer selected from 0 to 5; R 1 to R 7, and R 21 are each independently selected from a hydrogen, a deuterium, -F, -Cl, -Br, -I, a cyano group, a C 1 -C 20 alkyl group, a C 1 -C 20 alkoxy group, and one of Formulae 4-1 to 4-31: In Formulae 4-1 to 4-31, Y 31 is O, S, C(Z 33)(Z 34), N(Z 35), or Si(Z 36)(Z 37); wherein Z 31 to Z 37 are each independently selected from a hydrogen, a deuterium, -F, -Cl, -Br, -I, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid or a salt thereof, a sulfonic acid or a salt thereof, a phosphoric acid or a salt thereof, a C 1 -C 20 alkyl group, a C 1 -C 20 alkoxy group, a phenyl group, a naphthyl group, an anthracenyl group, a pyrenyl group, a phenanthrenyl group, a fluorenyl group, a chrysenyl group, a carbazolyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a pyridinyl group, a pyrimidinyl group, a triazinyl group, a quinolinyl group, an isoquinolinyl group, a quinazolinyl group, and a quinoxalinyl group; e1 is an integer selected from 1 to 5, e2 is an integer selected from 1 to 7, e3 is an integer selected from 1 to 3, e4 is an integer selected from 1 to 4, e5 is an integer of 1 or 2, e6 is an integer selected from 1 to 6, and * indicates a binding site with a neighboring atom, b1 to b3, and b21 are each independently an integer selected from 1 to 5; c1 is an integer selected from 1 to 4; and c2 is an integer selected from 1 to 4.