March 14 – COVID-19 pandemic: A man dies from COVID-19 at the Veterans Affairs Medical Center in Portland, becoming the first person in the state known to have died from the virus.
March 23 – COVID-19 pandemic: Governor Kate Brown issues a stay-at-home order.
April
April 13 – COVID-19 pandemic: Oregon joins Washington and California in creating the Western States Pact, an agreement to ease back each state's COVID-19 restrictions.
April 29
COVID-19 pandemic: The state reports its 100th death from COVID-19.
A man is struck and killed by an Amtrak train in Salem.
May 5 – COVID-19 pandemic: Cycle Oregon cancels all events for the year.
May 7 – COVID-19 pandemic: Governor Kate Brown announces a ban on large gatherings, expected to last until at least September. The Oregon State Fair is canceled almost immediately.
May 13 – Organizers announce that the 2020 Hood to Coast is cancelled due to COVID-19 restrictions.
May 19 – Oregon marks the end of primary voting for the Democratic and Republican parties.
May 20 – A kitten with two faces is born at a farm in Albany.
June 5 – George Floyd protests: U.S. District Judge Marco A. Hernandez issues a temporary restraining order that restricts the Portland Police Bureau's use of tear gas so that it should only be used during riots, although the order defines a "riot" as involving as few as five people.
June 8
George Floyd protests: Protesters shut down I-84 in Portland.
Amid daily protests in Portland, Portland Police Chief Jami Resch steps down, and is succeeded by Chuck Lovell.
June 26 – George Floyd protests: Protesters and the city agree to expand the restraining order on tear gas so that it also applies to rubber bullets and pepper spray.
July
The elk fountain in Portland on July 2, 2020, after removal of the statue
July 11 – George Floyd protests: Federal agents shoot a protester in the head with a projectile, causing skull fractures and facial injuries requiring facial reconstruction surgery.
The Northern Oregon Regional Correctional Facility (NORCF) announces that they will end their contract with ICE, leaving the state without any facilities to hold people detained by federal immigration officials.
August 25 – A patient scales the wall of the Oregon State Hospital and briefly escapes, running for half of a mile before hospital staff catch up with her.
September 9 – Two people are killed by wildfires southeast of Salem; these are the first deaths of the year that are confirmed to have been caused by wildfires.
November 3 – Oregon holds elections for president, state representatives, ballot measures, and other issues.
December
December 4 – COVID-19 pandemic: The Oregon Health Authority announces the state's 1,000th death from COVID-19.
December 21 – A group of protesters breach the Oregon State Capitol, aided by Representative Mike Nearman, during a closed emergency session. The protesters engage in violent confrontations with police and are forced out of the building.
Deaths
January 2 – Nick Fish (born 1958), politician and lawyer who served on the Portland City Council