William Van Alen was an American architect, best known for designing New York City's, art-deco Chrysler Building.

Van Alen attended the Pratt Institute in Brooklyn, and also studied for three years at the Atelier Masqueray, the first independent architectural atelier in the United States, founded by Franco-American architect Emmanuel Louis Masqueray.

Thereafter, Van Alen worked in New York, notably working on the Hotel Astor in 1902 for Clinton & Russell, before he was awarded the Paris Prize scholarship in 1908. The scholarship led to his studying in Paris, in the atelier of Victor Laloux at the Ecole des Beaux-Arts.

When Van Alen returned to New York in 1911, he formed a partnership with H. Craig Severance. The partnership became known for its distinctive multistory commercial structures. Their friendship grew strained over time, and eventually the partnership dissolved. Thereafter, both Severance and Van Alen continued to practice on their own in New York.

In the late 1920s, both architects found themselves engaged in designing buildings that were heralded in the press to become the tallest buildings in the world: Severance, the Manhattan Trust Building 40 Wall Street and Van Alen, the Chrysler Building. At 1046 feet, Van Alen's building won. However, both buildings were surpassed in height by the Empire State Building in 1931.

Van Alen had failed to enter into a contract with Walter Chrysler when he received the Chrysler Building commission. After the building was completed, Van Alen requested payment of 6 percent of the building's construction budget ($14 million), a figure that was the standard fee of the time. After Chrysler refused payment, Van Alen sued him and won, eventually receiving the fee. The lawsuit significantly depreciated his reputation as an employable architect. His career effectively ruined by this and further depressed by the Great Depression, Van Alen focused his attention on teaching sculpture.