In the present study, we theoretically analysed the corrosion inhibition performances of some novel 8-Hydroxyqionoline derivatives, namely 5-(((2-hydroxyethyl) thio) methyl) quinolin-8-ol (Q-OH) and 5-(((2-aminoethyl) thio) methyl) quinolin-8-ol (Q-NH2) against the corrosion of mild steel. In the section about DFT and HF calculations of the study, quantum chemical descriptors like frontier orbital energies, HOMO-LUMO energy gap, chemical hardness, electronegativity, softness, chemical potential, electrophilicity, nucleophilicity, proton affinity, electrons transferred from inhibitor to metal surface, electron-donating power, electron-accepting power, dipole moment, polarisability regarding protonated and neutral forms of the mentioned molecules were calculated and commented. In the section including the use of Molecular Dynamics Simulation approach of the analysis, adsorption behaviours of studied organic molecules on Fe (110) surface were investigated. To detect the power of the interactions between novel 8-Hydroxyqionoline derivatives and the mentioned metal surface, adsorption energy and binding energy values were calculated. It is important to note that these resuls determined are in good agreement with experimentally observed results. In addition to these analyses made, the validities of chemical reactivity principles such as Maximum Hardness, Minimum Polarisability and Minimum Electrophilicity Principles in corrosion inhibition studies were also reported.