The L. B. Day Amphitheatre (formerly the L. B. Day Comcast Amphitheatre) is an outdoor concert venue in Salem, Oregon, United States, within the Oregon State Fairgrounds. It was completed in 1987 with 9,000 seats, and named for L. B. Day, an Oregon State Senator and longtime supporter of the State Fair. In 1991, the venue was expanded to 14,000 seats to make it the largest arena of its type in Oregon at that time.