We searched for extreme emission line galaxies (EELGs) in the J-PLUS multiband survey (Cenarro et al., 2019A&A...622A.176C). We selected them by their excess of flux in the J0515 medium band filter, covering the [OIII] emission line doublet at z<0.06. Over the 2000 square degrees observed in the second data release of the survey, we identified 466 EELGs with equivalent width (EW) above 300 Ansgroms in [OIII], after removing higher redshift contaminants using infrared data. Most of the galaxies are compact and 411 of them were previously unknown. We perform spectral energy distribution (SED) fitting using CIGALE (Boquien et al., 2019A&A...622A.103B, Cat. J/A+A/622/A103) and we find that the sample has low stellar mass (M_star_~10^8.1^M_{sun}_), low metallicity, little dust extinction, and very young star formation bursts (~3Myr). This selection is 20 times more efficient finding EELGs than previous broadband surveys, and as complete as magnitude-limited spectroscopic surveys while reaching fainter targets.