An air-oil separation system for a gas turbine engine, the air-oil separation system comprising: a housing that extends circumferentially around an axis to define an interior chamber of the housing and including a first end wall, a second end wall, and a divider plate arranged between the first end wall and the second end wall, the divider plate cooperating with the second end wall to form a drive chamber therebetween, the housing formed to include an inlet configured to receive a mixture of air and oil, an oil outlet configured to conduct oil substantially free of air to exit the housing, and an air outlet configured to conduct air substantially free of oil to exit the housing, the inlet formed to receive the mixture of air and oil collected in an engine sump and guide the mixture of air and oil into the interior region, the mixture of air and oil flowing from the engine sump to a pump configured to direct the mixture of air and oil into the air-oil separation system through the inlet, an air-separation shaft located in the interior chamber of the housing and extending between the first end wall and the second end wall, the air-separation shaft configured to rotate about the axis relative to the housing during use of the air-oil separation system, the air-separation shaft formed to include an air passage that extends axially through the air-separation shaft and a plurality of air holes that extend radially through the air-separation shaft and open into the air passage, and the air passage being in fluid communication with the air outlet so that air located in the interior chamber is separated from oil and conducted through the plurality of air holes into the air passage and out of the air outlet during operation of the air-oil separation system, an oil-separation rotor located in the interior chamber of the housing, extending between the divider plate and the first end wall, and arranged circumferentially around the air-separation shaft, the oil-separation rotor being rotatably coupled with the air-separation shaft for rotation about the axis relative to the housing during use of the air-oil separation system, the oil-separation rotor formed to include a plurality of oil holes (76, 78) that extend radially through the oil-separation rotor to cause oil located in the interior chamber to be separated from air and conducted radially outward through the plurality of oil holes (76, 78) toward the housing and out of the oil outlet during operation of the air-oil separation system, and an impeller rotatably coupled with the air-separation shaft and configured to drive rotation of the air-separation shaft and the oil-separation rotor about the axis. a housing that extends circumferentially around an axis to define an interior chamber of the housing and including a first end wall, a second end wall, and a divider plate arranged between the first end wall and the second end wall, the divider plate cooperating with the second end wall to form a drive chamber therebetween, the housing formed to include an inlet configured to receive a mixture of air and oil, an oil outlet configured to conduct oil substantially free of air to exit the housing, and an air outlet configured to conduct air substantially free of oil to exit the housing, the inlet formed to receive the mixture of air and oil collected in an engine sump and guide the mixture of air and oil into the interior region, the mixture of air and oil flowing from the engine sump to a pump configured to direct the mixture of air and oil into the air-oil separation system through the inlet, an air-separation shaft located in the interior chamber of the housing and extending between the first end wall and the second end wall, the air-separation shaft configured to rotate about the axis relative to the housing during use of the air-oil separation system, the air-separation shaft formed to include an air passage that extends axially through the air-separation shaft and a plurality of air holes that extend radially through the air-separation shaft and open into the air passage, and the air passage being in fluid communication with the air outlet so that air located in the interior chamber is separated from oil and conducted through the plurality of air holes into the air passage and out of the air outlet during operation of the air-oil separation system, an oil-separation rotor located in the interior chamber of the housing, extending between the divider plate and the first end wall, and arranged circumferentially around the air-separation shaft, the oil-separation rotor being rotatably coupled with the air-separation shaft for rotation about the axis relative to the housing during use of the air-oil separation system, the oil-separation rotor formed to include a plurality of oil holes (76, 78) that extend radially through the oil-separation rotor to cause oil located in the interior chamber to be separated from air and conducted radially outward through the plurality of oil holes (76, 78) toward the housing and out of the oil outlet during operation of the air-oil separation system, and an impeller rotatably coupled with the air-separation shaft and configured to drive rotation of the air-separation shaft and the oil-separation rotor about the axis.