Lothar Meyer was born in Varel, Germany (then part of the Duchy of Oldenburg). He was the son of Friedrich August Meyer, a physician, and Anna Biermann.

After attending the Altes Gymnasium in Oldenburg, Lothar studied medicine at the University of Zurich in 1851.

After graduating as a Doctor of Medicine from Würzburg in 1854, Lothar went to the University of Heidelberg, where Robert Bunsen held the chair of chemistry.

In 1858, Lothar received a Ph.D. in chemistry from the University of Breslau with a thesis on the effects of carbon monoxide on the blood. With this interest in the physiology of respiration, he had recognized that oxygen combines with the hemoglobin in blood.

Influenced by the mathematical teaching of Gustav Kirchhoff, Lothar took up the study of mathematical physics at the University of Königsberg under Franz Ernst Neumann and in 1859, after having received his habilitation (certification for university teaching), became Privatdozent in physics and chemistry at the University of Breslau.

His book, Die modernen Theorien der Chemie, which he began writing in Breslau in 1862 and which was published two years later, contained an early version of the periodic table containing 28 elements, classified elements into six families by their valence—for the first time, elements had been grouped according to their valence. Works on organizing the elements by atomic weight, until then had been stymied by the widespread use of equivalent weights for the elements, rather than atomic weights.

In 1866, Meyer accepted a post at the Eberswalde Forestry Academy at Neustadt-Eberswalde but two years later was appointed to a professorship at the Karlsruhe Polytechnic.

Meyer married Johanna Volkmann in 1866.

In 1869, Dmitri Mendeleev published a periodic table of all elements known at that time (he later predicted several new elements to complete the table, and corrected some atomic weights).

In 1872, Meyer was the first to suggest that the six carbon atoms in the benzene ring (that had been proposed a few years earlier by August Kekulé) were interconnected by single bonds only, the fourth valence of each carbon atom being directed toward the interior of the ring.

During the Franco-Prussian War, the Polytechnic was used as a hospital and Meyer took an active role in the care of the wounded. In 1876, Meyer became Professor of Chemistry at the University of Tübingen.

In 1882, both Meyer and Mendeleev received the Davy Medal from the Royal Society in recognition of their work on the Periodic Law.

Meyer served until his death from a stroke on April 11, 1895 at the age of 64.

On 19 August 2020, Google celebrated his 190th birthday with a Google Doodle.