Ethanolic extracts of olive leaves (OLE) in the presence of TiCl4 solution was used to form OLE - Ti nanoparticles composite (OLE-Nano). The particle size of Ti nanoparticles in the composite was determined using particle sizer and the nanoparticles were characterized using UV-vis, FTIR, SEM/EDAX and XRD techniques. Results show that the particles were around 70-74nm in size and show maximum absorption around 420nm. Prominent FTIR peaks correspond to C=C, N-H, O-H and C=O functionalities. XRD spectrum shows four distinctive diffraction peaks at 27.42 degrees, 36.07 degrees, 41.23 degrees, and 54.30 degrees corresponding to lattice plane value indexed at (101), (104), (200) and (211) planes of face centered cubic (FCC). The anticorrosion property of the OLE-Nano for mild steel in 1M HCl at 30-60 degrees C was assessed using weight loss and electrochemical techniques complemented by surface analysis of the corroded steel specimen in the absence and presence of OLE - Nano with SEM and AFM. Results obtained show that OLE inhibited the acid corrosion of mild steel and the inhibition performance was enhanced in the presence of Ti nanoparticles. The corrosion inhibition effect was found to be concentration and temperature dependent. The inhibition efficiency of the OLE and OLE-Nano were 83.5 and 94.3% respectively at 30 degrees C but decreased to 51.7 and 85.4% at 60 degrees C respectively. The OLE-Nano adsorbed on mild steel surface by physical adsorption mechanism as predicted by Langmuir adsorption isotherm model. Potentiodynamic polarization results show that OLE-Nano behaves as mixed type inhibitor.