- Location: Eugene, OR
- League: Northwest League 1955-1968; Pacific Coast League 1969-1973; Northwest League 1974-2019; High-A West 2021; Northwest League 2022-
- Affiliation: Portland Beavers 1956; Sacramento Solons 1957; San Francisco Giants 1959-1962; Chicago White Sox 1963; Philadelphia Phillies 1964-1965; Philadelphia Phillies & St. Louis Cardinals 1966; Philadelphia Phillies 1967-1973; Co-op 1974; Cincinnati Reds 1975-1983; Kansas City Royals 1984-1994; Atlanta Braves 1995-1998; San Diego Padres 2001-2014; Chicago Cubs 1999-2000, 2015-2019; San Francisco Giants 2021-Present
- Ballpark: Bethel Park 1955-1968; Civic Stadium 1969-2009; PK Park 2010-present
The Eugene Emeralds, of the Northwest League and briefly in High-A West, had the NwL's worst overall record in 2018 but made the playoffs as a wild card - and won out for the crown! The San Francisco Giants farmhands play their home games at PK Park in Eugene, OR.
Early editions of the Ems played at Bethel Park, but the expansion of 1969 that begat the Seattle Pilots bumped the Pacific Coast League's Seattle Angels team to Eugene, where they moved into Civic Stadium. The NwL returned in 1974, again choosing Civic. They moved into PK Park in 2010, a park originally built when the University of Oregon resumed its baseball program. Civic Stadium fell victim to arson in June 2015. On the August night that the Emeralds commemorated it, four Ems pitchers hurled a combined no-hitter.
The Ems play Copa de la Diversión Hispanic engagement campaign games as Monarcas de Eugene (Eugene Monarchs, which can either refer to emperors or to monarch butterflies).