What happened October 2019 AD in United States of America

At WWE SmackDown's 20th Anniversary, Johnson would cut a promo with Becky Lynch before they were interrupted by King Corbin. After attacking Corbin, The Rock and Lynch celebrated in the ring.

macOS 10.14 Mojave was succeeded by macOS 10.15 Catalina in 2019, which replaces iTunes with separate apps for different types of media, and introduces the Catalyst system for porting iOS apps.

The fourth debate was held on October 15 in Westerville, Ohio. During the debate, Yang discussed topics including impeachment, automation, the economy, taxation, foreign policy, the opioid crisis, big tech, and personal data as a property right, speaking for 8 minutes and 32 seconds, the fourth-least time of any candidate. He proposed decriminalizing opioids, a stance candidate Beto O'Rourke agreed with. Candidates Julian Castro and Tulsi Gabbard said Yang's Freedom Dividend policy "was a good idea, and something they would consider if elected president", while candidate Cory Booker argued that a $15 minimum wage was superior to UBI. Yang also spoke about the potential impeachment inquiry against Donald Trump, saying he supports impeachment, but that "we should not have illusions that impeaching Donald Trump will, one, be successful or, two, erase the problems that got him elected in 2016.

During the Asian hard court season, Kenin won one additional title in both singles and doubles. She won her third singles title of the year at the Guangzhou International Women's Open, defeating Samantha Stosur in the final. Two weeks later, she partnered with Bethanie Mattek-Sands to win her second doubles title of the year at the China Open, a Premier Mandatory event. During the event, the pair defeated the team of Aryna Sabalenka and Elise Mertens, who were ranked No. 2 and No. 3 in the world respectively at the time. This title brought her to No. 43 in the doubles rankings. At the end of the season, Kenin qualified for the WTA Elite Trophy as the second seed, ranked No. 12 in the world. She won her opening match against compatriot Alison Riske, but lost to Karolína Muchová and did not advance out of her round-robin group. Kenin was also named the second alternate at the WTA Finals, behind Kiki Bertens. After Naomi Osaka and Bianca Andreescu both withdrew, she had the opportunity to play one match, losing to the defending champion Elina Svitolina. She finished the year ranked No. 14 in singles and No. 39 in doubles. Kenin also received the WTA Most Improved Player of the Year award for her breakthrough season, becoming the first American player to win the award since Serena Williams in 1999.

On October 21, 2019, Trump mocked the Emoluments Clause as "phony".

In 2019 Riot Games celebrated the 10th anniversary of League of Legends. During an online stream, Riot announced a variety of new game projects based on the world of League of Legends, as well as in-game gifts which players would receive.