In the structure of the title salt, C20H20NO+�C6H4FO3S�, the 4-(ethoxyphenyl)ethenyl unit is disordered over two positions with a refined site-occupancy ratio of 0.610 (6):0.390 (6). The cation is nearly planar, the dihedral angle between the quinolinium and benzene rings being 6.7 (4) and 1.7 (7)� for the major and minor components, respectively. The ethoxy group is essentially coplanar with the benzene ring [C—O—C—Cmethy = 177.1 (8) and 177.8 (12)� for the major and minor components, respectively]. In the crystal, cations and anions are linked into chains along the b-axis direction by C—H� � �Osulfonyl weak interactions. These chains are further connected into sheets parallel to (001) by C—H� � �Osulfonyl weak interactions. The chains are also stacked along the a axis through �–� interactions involving the quinolinium and benzene rings [centroid–centroid distances = 3.636 (5) A ° for the major component and 3.800 (9) A ° for the minor component]. C—H� � �� interactions are also present.