James R. Mills Building, Government office tower in East Village, San Diego, United States.

The James R. Mills Building is a ten-story governmental office tower completed in 1989, trimmed in red, the color of the San Diego Trolley. Trolleys run through the base of the building at the 12th & Imperial Transit Center, and a 200-foot clock tower stands in the plaza in front. A 1,020-car garage adjoins it.

Construction was initiated in 1987 by the Metropolitan Transit Development Board and completed in 1989 as their administrative headquarters. The building was erected directly above the 12th Street transit station and became central to the city's public transportation infrastructure.

The building honours James R. Mills (1927–2021), the state senator who wrote the legislation creating the San Diego Trolley and chaired the Metropolitan Transit Development Board from 1985 to 1994. The red trim on the facade echoes the colour of the trolley cars.

Trolleys on both San Diego Trolley lines run through the base of the building at 12th & Imperial Transit Center, so transfers between lines happen under the same roof. A 1,020-space garage stands next to the tower, with paid parking for employees and MTS riders. The clock tower rises from the plaza in front of the entrance.

The clock was a gift from Swiss watchmaker Ebel, arranged by the Swiss banking official who helped sell the construction bonds. Shipped unassembled from Switzerland by jumbo jet, it was put together on site by Swiss technicians over 12 days. On December 1, 1988, the tower was dedicated as the Ebel Clock Tower.