Fourth Church of Christ, Scientist, Digital library headquarters in Richmond District, San Francisco, US

The Fourth Church of Christ, Scientist is a 1923 Classical Revival building at 300 Funston Avenue, at the corner of Clement Street in the Richmond District, designed by San Francisco architect Carl Werner with Corinthian columns. The roughly 23,000-square-foot structure now serves as the headquarters of the Internet Archive.

The building was constructed in 1923 as a church and designed by architect Carl Werner before later being repurposed for a completely different mission. This transformation marked a major turning point in the site's history.

Hymn numbers posted beside the stage are 200, 404 and 451, the HTTP codes for a loaded page, an error and a block for legal reasons. Since 2009 terracotta sculptures of staff who have worked at the Archive for over three years have stood in the main room.

The building at 300 Funston Avenue, at the corner of Clement Street in the Richmond District, is the Internet Archive's headquarters. Founder Brewster Kahle often leads a free public tour given every Friday after lunch. The auditorium, with hymn numbers on either side of the stage, is the room visitors see on the tour.

The hymn board beside the stage shows 200, 404 and 451, the HTTP codes for a page that loads, one that fails and one blocked for legal reasons. Servers along the back wall held about a tenth of the Archive's online material as of 2024. Since 2009 terracotta busts of staff with more than three years' service have stood in the room.