<p>The study aimed to develop and demonstrate the psychometric properties of the Brief Scale of Religiosity in Couples. For this, a pilot sample of 307 Peruvian adults of both sexes (56.4% male and 43.6% female) between the ages of 19 and 71 (<i>M</i> = 40.8; <i>SD</i> = 10.8) was collected. The confirmatory sample consisted of 401 Peruvian adults of both sexes (59.6% male and 40.4% female) between the ages of 19 and 68 (<i>M</i> = 40.2; <i>SD</i> = 10.1). The WHO-Five Well-Being Index was also applied in the confirmatory sample to measure people’s subjective well-being. Regarding the results, in the pilot study, the exploratory factor analysis evidenced the presence of a single factor that managed to explain 51% of the variability of the items. In the confirmatory study, the confirmatory factor analysis showed that the one-dimensional model with five items presented the best-fit indices compared to the seven-item model (χ² = 18.56; <i>df</i> = 5; <i>p</i> = .000; RMSEA = .082 [IC&#xa0;90% .045–.124]; SRMR = .024; CFI = .99; TLI = .99). The five items presented adequate discrimination and difficulty indices from the item response theory perspective. The scale also demonstrated evidence of being strictly invariant for the male and female groups. Finally, it was found that religiosity as a couple significantly predicted people’s subjective well-being (.52). It is concluded that the Brief Scale of Religiosity in Couples (RC-5) is a useful tool from which valid and reliable interpretations of couple religiosity can be obtained.</p>