The Sentinel's predecessors date to 1876, when the Orange County Reporter was first published. The Reporter became a daily newspaper in 1905, and merged with the Orlando Evening Star in 1906. Another Orlando paper, the South Florida Sentinel, started publishing as a morning daily in 1913. Then known as the Morning Sentinel, it bought the Reporter-Star in 1931, when Martin Andersen came to Orlando to manage both papers. Andersen eventually bought both papers outright in 1945, selling them to the Tribune Company of Chicago in 1965.
In 1973, the two publications merged into the daily Sentinel Star. Tribune appointed Charles T. Brumback as president in 1976. Harold "Tip" Lifvendahl was named president and publisher in 1981. The newspaper was renamed the Orlando Sentinel in 1982. John Puerner succeeded Lifvendahl in 1993, who was replaced by Kathleen M. Waltz in 2000. She announced her resignation in February 2008. Howard Greenberg, already publisher of fellow Tribune newspaper the Sun-Sentinel of Fort Lauderdale, was named publisher of both papers after Waltz left.
In 2008, the Tribune Company called for a redesign of the Sentinel. The new layout, which debuted in June 2008, was formatted to appeal to busy readers, though like all of the redesigns in Tribune's Sam Zell ownership era, was reeled back into a more traditional design with appealing elements kept after reader criticism.
According to one listing, some of the Sentinel's predecessors are:
Orlando Reporter: 1892–1903? (merged with Evening Star to form Evening Reporter-Star)
Evening Star: January–December 1903? (merged with Orlando Reporter to form Evening Reporter-Star)
Evening Reporter-Star: 1904?–March 1947 (continues Orlando Reporter and Evening Star; continued by Orlando Evening Star)
Orlando Evening Star: April 1947 – 1973 (continues Evening Reporter-Star; merged with Orlando Morning Sentinel to form the Orlando Sentinel-Star)
Orlando Morning Sentinel: 1913–1973 (title varies: Daily Sentinel; Morning Sentinel; merged with Orlando Evening Star to form the Orlando Sentinel-Star)
Orlando Sentinel-Star: 1974–April 25, 1982 (continues Orlando Morning Sentinel and Orlando Evening Star; continued by Orlando Sentinel)
Orlando Sentinel: April 26, 1982–present (continues Orlando Sentinel-Star)
In June 2019, the day of President Donald Trump's re-election campaign launch rally in Orlando, the Sentinel made national news when the editorial board published a piece saying it would not endorse the president, among their reasons, "the chaos, the division, the schoolyard insults, the self-aggrandizement, the corruption, and especially the lies." It ultimately endorsed Biden, saying that he was "many things that Trump is not now and never will be."