Altenahr (German pronunciation: [altn̩ˈʔaːɐ̯]) is a municipality in the district of Ahrweiler, in Rhineland-Palatinate, Germany.

Altenahr is a state-recognised tourist resort and is ranked as a Grundzentrum for state planning purposes.

Altenahr borders on the following neighbouring municipalities, listed clockwise from the north: Kalenborn, Grafschaft, Mayschoß, Ahrbrück, Lind and Berg.

On 7 June 1969 the hitherto independent municipality of Kreuzberg, with its 560 inhabitants, was incorporated into Altenahr.

[5] The growth in Altenahr's population related to the present-day municipal area; the values from 1871 to 1987 are based on censuses:[3][6]