0.8% of Tanjung Balai City's population is Catholic.

The Catholic population in Tanjung Balai City, as of December 31, 2023, was recorded at 1,463 individuals. This represents a decrease of 922 individuals compared to the previous year's reported figure of 2,385.

According to data from the Directorate General of Population and Civil Registration (Ditjen Dukcapil) of the Ministry of Home Affairs, the proportion of Catholics in this regency/city reached 0.8 percent of the total population in 2024, which numbered 186,150.

In terms of its distribution across the various regions of North Sumatra, the proportion of Catholics in Tanjung Balai City ranks 31st.

The following is a list of the population of North Sumatra by religion in 2023:

* Islam: 160,539 (86.24%)
* Protestant: 13,061 (7.02%)
* Buddhist: 8,497 (4.56%)
* Catholic: 1,463 (0.79%)
* Confucian: 37 (0.02%)
* Hindu: 32 (0.02%)
* Other Beliefs: 7 (0.0%)

Other regencies/cities in North Sumatra with the largest Catholic populations are: South Nias Regency (71,097), Medan City (63,276), Karo Regency (61,454), Simalungun Regency (57,719), Deli Serdang Regency (56,220), Samosir Regency (54,250), West Tapanuli Regency (45,287), Dairi Regency (37,671), Humbang Hasundutan Regency (27,328), and North Nias Regency (22,591).