Paul Oswald Ahnert (22 November 1897 – 27 February 1989) was a German astronomer. He first became famous in Germany for publishing the "Kalender für Sternenfreunde" from 1948 until 1988, an annual calendar of astronomical events. After the war he met the female astronomer Eva Rohlfs at Sonneberg Observatory and married her in 1952. His second marriage lasted only two years, because Eva died in 1954 in age of 41. During the 1950s Paul Ahnert advanced from an assistant observer to an astronomer with international reputation, who made important observations of variable stars and solar activity.