A limited number of longitudinal studies have explored factors contributing to decreases in tongue pressure (TP). This longitudinal study aimed to clarify the factors affecting TP decline among community-dwelling older adults. We followed the Takashimadaira Study participants with a baseline TP ≥ 30 kPa for 2 years. A TP of <30 kPa at follow-up was defined as TP decline. We used Poisson regression with robust standard errors to explore the factors related to TP decline. The studied baseline variables were dental status, sociodemographic characteristics, health behaviors, appetite, medical conditions, physical function, cognitive status, and anthropometric and body composition characteristics. Inverse probability weighting (IPW) was used to adjust for selection bias. Overall, 357 individuals (159 men and 198 women) with a mean (standard deviation) age of 75.9 (4.1) years were included in the analyses. Of these, 59 study participants (16.5%) exhibited TP decline. After adjusting for baseline TP and applying IPW, poor appetite (incident rate ratio [95% confidence interval] = 1.58 [1.01–2.48]), low skeletal muscle mass index (1.66 [1.02–2.70]), and cognitive impairment (1.93 [1.12–3.33]) were associated with TP decline. In conclusion, we demonstrated that baseline appetite, body composition, and cognitive status could predict future TP decline among community-dwelling older adults.