Architect Roy Place, who designed many of Tucson's significant early 20th-century buildings, established the visual language of the campus. His use of red brick set a precedent that has shaped nearly every subsequent building: red brick as either the primary facade material or a stylistic accent harmonizing new construction with the old. The 179-building main campus occupies 380 acres in central Tucson, roughly divided into quadrants by the grassy Mall stretching east from Old Main and Highland Avenue running north-south. Sciences cluster in the southwest, athletics in the southeast, arts and humanities in the northwest, engineering in the north-central area. Much of the campus has been designated an arboretum, with labeled plants from around the world along self-guided walks. The Krutch Cactus Garden contains the tallest Boojum tree in Arizona. Hundreds of olive trees, many over a century old, trace back to plantings by Professor Robert H. Forbes.

The Student Union Memorial Center was rebuilt between 2000 and 2003 with a deliberate architectural reference to the USS Arizona. Sculptures throughout the building honor military service, including dog tags that chime in the desert wind and prisms refracting light across interior spaces. The centerpiece arrived on campus in July 1946: one of two bells rescued from the battleship after the December 7, 1941 attack on Pearl Harbor. For decades, the bell rang seven times at 12:07 PM on the third Wednesday of every month -- symbolic of the date and time of the sinking -- as well as after home football victories against non-Arizona opponents. In December 2020, at the request of the U.S. Navy, which still officially owns the bell, the ringing stopped to preserve the historic artifact. The bell remains on permanent display in the clock tower.

The Wildcat name dates to a 1914 football game against Occidental College, then California state champions. The Los Angeles Times reported that 'the Arizona men showed the fight of wildcats,' and the nickname stuck. The university's first mascot, introduced in 1915, was an actual desert bobcat named Rufus Arizona. Today's mascots are the anthropomorphized Wilbur and Wilma, whose human operators remain anonymous. In 1986, Wilbur married his longtime girlfriend Wilma in a campus ceremony. The athletic program joined the Big 12 Conference in 2024 after decades in the Pac-12. The men's basketball team, under Hall of Fame coach Lute Olson, made 25 consecutive NCAA tournament appearances from 1985 to 2009 and won the 1997 national championship. The softball team has reached the NCAA championship game 12 times, winning eight titles, most recently in 2007.

The University of Arizona has become synonymous with optical and space sciences. The Steward Observatory Mirror Lab, located beneath Arizona Stadium, is one of the few facilities in the world capable of casting the enormous mirrors used in major telescopes. The spinning furnace technique developed here produces mirrors with parabolic surfaces that would be impossible to grind conventionally. This expertise, combined with the university's planetary science and astronomy programs, has helped Tucson earn the nickname 'Optics Valley.' Roughly 150 Tucson companies now work in optics and optoelectronics. The Wyant College of Optical Sciences trains students in technologies ranging from medical imaging to defense applications. Major research centers include the Lunar and Planetary Laboratory, which has operated instruments on multiple Mars missions, and the Arizona Health Sciences Center with its two affiliated medical centers in Tucson and Phoenix.

The university has faced significant challenges in recent years. In 2002, three professors were murdered by a former student who had failed out of the program. In October 2022, another professor was killed on campus by a former student, prompting an independent safety investigation and a faculty senate vote of no confidence in university leadership. A 2020 acquisition of the for-profit Ashford University, renamed the University of Arizona Global Campus, drew criticism from faculty and attracted investigations from multiple state attorneys general. By 2023, the university acknowledged losing track of more than $240 million through accounting errors and flawed financial projections, with much of the crisis linked to the Ashford acquisition. Despite these difficulties, research and enrollment have continued to grow, and the distinctive red-brick campus remains the intellectual heart of southern Arizona.