Seed dormancy and germination are critical in the life cycle of higher plants. Plant protein phosphatase 2C (PP2C) plays crucial roles in phytohormone signaling, developmental processes, and responses to biotic and abiotic stresses. DELAY OF GERMINATION 1 (DOG1) is the causal gene for a major quantitative trait locus (QTL) of seed dormancy and is a member of a small gene family in Arabidopsis thaliana. Interactions between DOG1 and group A PP2Cs have been reported in Arabidopsis. However, our knowledge about the molecular interactions between DOG1-like proteins (DOG1Ls) and group A PP2Cs and their involvements in the regulation of seed dormancy remains largely unknown in wheat (Triticum aestivum L.). Yeast-two hybridization results showed that TaDOG1L1 and TaDOG1L2 interacted with TaPP2C-a7. The qRT-PCR analysis showed that TaPP2C-a7 expression was induced under the ABA treatment. In addition, TaPP2C-a7 expression was responsive to the PEG and NaCl treatments. TaPP2C-a7 interacted with the subclass III TaSnRK2s; by contrast, TaPP2C-a7 conditionally interacted with TaPYL4 only in the presence of ABA. TaMyb1D and TaMybU bound to the MBS elements in the TaPP2C-a7 promoter, possibly regulating the expression of TaPP2C-a7 under drought conditions. Further investigations demonstrated that overexpression of TaPP2C-a7 in Arabidopsis promoted seed germination and decreased the sensitivity to ABA during germination. Additionally, TaPP2C-a7 overexpression plants of Arabidopsis exhibited decreased tolerance to drought stress. Overall, these results improve our understanding of the functions of TaPP2Cs and provides useful information for wheat breeding.