Extreme ultraviolet spectra of highly charged barium atoms were produced with an electron beam ion trap (EBIT) and recorded with a flat-field grazing-incidence spectrometer. The spectra were measured in the wavelength range 4 nm–24 nm with the beam energies varying from 700 eV to 30 000 eV. The line identifications were performed with collisional-radiative modeling of the EBIT plasma that provided good quantitative agreement between simulated and measured spectra. In the energy range 700 eV–1750 eV, fifty three n = 4–n = 4 transitions in Se-like (Ba22+) to Cu-like (Ba27+) ions were identified, with forty seven corresponding to new lines. Almost all lines are due to electric-dipole transitions. For the beam energies of 3945 eV–7530 eV, we identified eight new n = 3–n = 3 transitions in Ba42+ (Si-like), Ba43+ (Al-like), and Ba44+ (Mg-like). At the highest beam energy, 30 000 eV, three new n = 2–n = 2 transitions of Ba51+ (B-like), Ba52+ (Be-like), and Ba53+ (Li-like) were identified. The measured wavelengths are compared with recent ab initio theoretical calculations. An improved ionization energy for Ba26+ (Zn-like), IE = 937.2 ± 0.8 eV, was determined by comparing theoretical values with measurements along the Zn isoelectronic sequence.