A magnetic tunnel junction (MTJ) is a device in which a barrier layer is sandwiched between two ferromagnetic (FM) layers. In this work, iron (Fe), nickel (Ni), and cobalt (Co) are considered as ferromagnetic layers, and strontium oxide (SrO) is considered as a barrier layer. The magnetic anisotropy energy (MAE) of the tunnel junction is investigated using density functional theory (DFT). The calculated MAE for Fe/SrO/Fe, Ni/SrO/Ni, and Co/SrO/Co junctions is 1.57 meV, −0.18 meV, and −0.02 meV, respectively. It indicates that out-of-plane magnetization is more preferred for Fe/SrO/Fe junction, and in-plane magnetization is more preferred for Ni/SrO/Ni and Co/SrO/Co junctions. The d-orbital of Fe, Ni, and Co atoms primarily contributes to the MAE. The exchange stiffness (Aex) of Fe/SrO/Fe, Ni/SrO/Ni, and Co/SrO/Co junctions was calculated and found to be 238.31, 466.48, and 722.42 meVÅ2, respectively. The Co/SrO/Co junction showed the highest Aex value, whereas the Fe/SrO/Fe junction showed the least Aex value. Overall, the d-orbitals of transition metal atoms located near the interface are crucial in influencing magnetic anisotropy energy, a key factor in developing thermally stable spintronic memory devices.