The discovery of oxygen is credited to Carl Wilhelm Scheele, a Swedish chemist and pharmacist, in 1771. However, he did not initially recognize it as a distinct element. He called it "fire air" because it supported combustion.

Joseph Priestley, an English chemist, independently discovered oxygen in 1774. He named it "dephlogisticated air" and recognized its role in respiration.

While both Scheele and Priestley played significant roles in the discovery of oxygen, it was Antoine Lavoisier who established its true nature as an element and gave it the name "oxygen" in 1777. He understood that oxygen was a component of air and essential for combustion and respiration.