Type 2 diabetes mellitus (T2DM) is associated with higher severity and mortality in SARS-CoV-2 infections. Vaccination has been encouraged to boost immunity and prevent these unfortunate outcomes. Few studies have evaluated antibody levels after COVID-19 vaccination in patients with T2DM. Therefore, we examined the vaccination status and anti-SARS-CoV-2 antibody levels to identify the factors that affect the antibody levels in patients with T2DM. This cross-sectional study was conducted at the Dr. Hasan Sadikin Hospital and Bandung Kiwari Hospital, Bandung, West Java, Indonesia, between October and November 2022. Adult participants with and without T2DM were tested for SARS-CoV-2 antibodies using a point-of-care quantitative immunochromatographic assay. We enrolled 289 participants: 201 participants with T2DM and 88 participants without T2DM. The T2DM participants had a lower vaccination rate compared with the non-T2DM participants. However, no significant differences in antibody levels were observed between the two groups. Higher antibody levels among the T2DM participants were associated with mRNA vaccination and a history of COVID-19 illness. The lower antibody response observed among the T2DM participants with chronic obstructive pulmonary disease suggests that such patients may need antibody level measurement and an additional booster vaccine.