As is the case with a lot of other Western RPGs these days, romance plays a fairly important role in Starfield. However, despite there being more than twenty possible companions in the game, only four of them are romanceable; these being Andreja, Barrett, Sam, and Sarah.
Starfield Romance Guide (All Romanceable Companions)
Like most Western RPGs, Starfield features romance options, although only four of the game's 20+ companions can actually be seduced by the player.