Bread can be a major contributor to sodium intake, but sodium chloride reduction poses difficulties since it influences the functional properties of dough and flavor of bread. This study evaluated dough and bread properties in reduced-sodium systems containing fermented or unfermented macroalgae Saccharina latissima or Alaria esculenta. Recipes contained equal amounts of sodium (4 mg Na+/g flour), where sodium chloride contributed 3 or 3.5 mg Na+/g flour and 8.9–33.3 mg macroalgae/g flour contributed the remaining 0.5 or 1 mg Na+/g flour. A full-salt and three salt-reduced controls (6, 4, 3.5, and 3 mg Na+/g flour) were used for comparison. Empirical dough rheology, stickiness, ratios of polymeric to monomeric proteins, and bread characteristics (specific volume, crumb structure, and firmness) were measured. A trained sensory panel conducted a descriptive sensory analysis. Macroalgae addition increased water absorption and decreased dough development time, dough stability, the polymeric to monomeric protein ratio, and specific volume in a dose-dependent manner. Macroalgae addition increased the perception of saltiness, but also algae flavor and odor. Bread with fermented S. latissima received lower scores for certain undesirable sensory attributes than other bread with algae.