Analyzing a city's registry offers insights into its population makeup. Barcelona's numbers have gently risen to 1.7 million, driven by increasing migrant arrivals. Foreign nationals now constitute 26.4% of the populace, while only 45% are city-born. However, the residential composition reveals intriguing shifts; solo households are on the rise, comprising 31.6% of the total, or 215,153 residences. This surpasses the Spanish average of 28%.

In these single-person homes, women lead the trend, making up 61% compared to men's 39%. María Jesús Calvo, head of the Statistics and Data Dissemination department, describes this as a “solid phenomenon” that has expanded significantly in recent years. The report from the Municipal Data Office notes: “The more developed the welfare state, the greater the likelihood of living alone. As women increasingly join the workforce, they become less dependent and more inclined to solo living.”

The report adds that factors like autonomy, privacy, increased life expectancy (especially among women), and advancements in telecommunications bolster the growth of solo households. Over the past 28 years, the gender gap has narrowed, and single male households have risen by 23%. Beyond solo homes, two-person households make up 29%, while those with three or four members account for 21%.

A broader trend from the domicile data shows a steady increase in homes over nearly three decades, while the number of occupants per residence has decreased. Since 1997, homes have grown by almost 100,000, with occupancy dropping from 2.7 to 2.48 persons per household. Recently, a slight rise in occupancy suggests a future investigation into living conditions surveys may be needed.

Overall, Barcelona's registry as of January 1 reflects steady trends, yet at a slower pace: population growth continues, but more gradually, and the proportion of foreign residents rises, albeit slowly. Barcelona's population now stands at 1,732,066, marking a 30,000 increase over the previous year—a 1.7% rise—and the highest figure in 40 years. Birth and death rates have stabilized, and migration patterns have reached equilibrium. The average age is 44.4 years, with life expectancy between 85-86 for women and 80 for men. Population growth is evident in 70 out of 73 neighborhoods, with notable increases in La Clota and La Marina del Prat Vermell due to new housing developments.

Centenarians are also increasing, with 1,104 individuals, 84% of whom are women. The educational attainment among those over 16 shows that 37% have university degrees or advanced vocational training. In terms of birthplace, Barcelona continues to lose native-born residents; as of 2025, only 45% are city-born. Among foreign-born residents, Argentina, Colombia, and Peru are the top countries of origin. In terms of nationality, 26.4% of Barcelona's population is foreign, with the most common nationalities being Italian, Colombian, Pakistani, Chinese, and Peruvian. The city hosts 182 nationalities, with recent additions being Saint Lucia and Timor-Leste.