This study was undertaken to evaluate the response of “Manzanillo" olive (Olea europea L.) seedlings to unconventional nitrogen applications and growth stimuli treatments on growth parameters and plant chemical compositions. A pot experiment was carried out during two consecutive seasons of 2018 and 2019: from March to October of each season at the Experimental Farm of Plant Production Dept. Fac. Environ. Agric. Sci., Arish Univ. Egypt. An approximate one-year-old uniform “Manzanillo" olive seedlings were transferred into black polyethylene bags (30 cm diameter and 40 cm depth) filled with 4.0 kg growth media q.e. mixture of sandy soil and peat moss at mixture ratio of 4:1 by volume. Olive seedlings were sprayed with different sources of nitrogen (0.0 mg N L^-1as control, 500 mg nano-N L^-1 and 1000 mg urea L^-1) followed with growth stimuli additions (humic acid, amino acid and humic acid+amino acids) at different intervals. The obtained results showed that three times application of nano-N foliar fertilizer in combination with humic+amino acids improved plant growth characteristics such as root system, vegetative growth, pigments and leaf nutrients content. Moreover, using N fertilizer in the form of nanoparticles reduced the required amount of N to plant comparing with traditional form of N reflected on saving the environment from contamination and the loss of access addition of traditional N fertilizer by leaching or ammonification. In general, the foliar application of N fertilizer at different forms was the easiest way to fertilize olive plant and most suitable for plant absorption process.