The Florida boom resulted in the construction of many significant structures in Lakeland, a number of which are today listed on the National Register of Historic Places. This list includes the Terrace Hotel, New Florida Hotel (Regency Towers), Polk Theatre, Promenade of Lake Mirror, Polk Museum of Art (not a product of the 20's boom), Park Trammell Building (formerly the Lakeland Public Library and today the Lakeland Chamber of Commerce), and others. The city also has several historic districts with many large buildings built during the 1920s and 1940s. The Cleveland Indians held spring training here from 1923 to 1927 at Henley Field Ball Park. Many new parks have been privately funded surrounding Lake Mirror. They are the Barnett Children's Park, Hollis Gardens, and the newest, Allen Kryger Park.

The "boom" period went "bust" quickly, and years passed before the city recovered. Part of the re-emergence was due to the arrival of the Detroit Tigers in 1934 for spring training. (The team continues to train at Lakeland's Joker Marchant Stadium and owns the city's Florida State League team, the Lakeland Flying Tigers.) The development of the Lakeland Municipal Airport as a major facility in central Florida transportation was another factor. The 1930’s also featured the arrival of renowned architect Frank Lloyd Wright. In 1938 he came to Lakeland at the request of Florida Southern College President Ludd Spivey to design a "great education temple in Florida." For 20 years Wright worked on his "true American campus" creation. In his original master plan he called for 18 buildings (and several other structures), 9 of which were completed and nine left on the drawing board. All of the buildings were built out of what Wright called his "textile block system," the first use of such a system in Florida. He called his project "A Child of the Sun," so named from the architect’s own description of being "out of the ground, into the light, a child of the sun." It is the largest one-site collection of Frank Lloyd Wright buildings in the world, and in many ways helped to form a pattern for many colleges in Florida and other areas of the country in the future years.

During World War II, Lakeland made an important contribution which directly contributed to the defeat of Hitler. Hundreds of young British men were taught to fly at Lakeland's Lodwick airfield by volunteer flight instructors, a collection of barnstormers and independent pilots. These British airmen enjoyed the hospitality of Lakeland during their training, then returned home to fight the Battle of Britain. Their skills in shooting down German warplanes was crucial to Britain's survival. When America entered the war, the Army Air Corps relied on training fields like Lodwick to supply pilots for its fighters, bombers and transport planes.

In 1990 Lakeland made its Hollywood debut when the Southgate Shopping Center was featured in the hit movie Edward Scissorhands starring Johnny Depp and Winona Ryder.

It is also mentioned near the end of the Sublime song April 29, 1992 (Miami) when lead singer Bradley Nowell lists the cities burning across the United States.

Lakeland made national headlines on 28 September 2006 when Polk County Sheriff's Deputy Vernon "Matt" Williams and his K-9 partner, Diogi, were shot and killed after a routine traffic stop in the Kathleen area of the town. The incident sparked outrage among the central Florida law enforcement community. More than five-hundred law officials came together in search of Angilo Freeland, the suspect wanted in connection with the murder. The next morning Freeland was found hiding under a fallen tree. He was shot 68 times, and died on the scene. Deputy Williams and Diogi were laid to rest on 3 October 2006 after a funeral that included an one-hour and 45 minute procession to Auburndale.

Lakeland is home to one of the first Hindu temples in the United States. Publix Super Markets is also headquartered here. The first Red Lobster restaurant was opened here; however the original restaurant has since closed.