Actresses with the most Best Supporting Actress nominations (in parentheses) include:
Thelma Ritter (6) - no wins; nominated for All About Eve (1950), The Mating Season (1951), With a Song in My Heart (1952), Pickup on South Street (1953), Pillow Talk (1959) and Birdman of Alcatraz (1962); nominations were in a 12-year span from 1950-1962 (four nominations were consecutive in a streak from 1950-1953)
Amy Adams (5) - no wins; nominated for Junebug (2005), Doubt (2008), The Fighter (2010), The Master (2012) and Vice (2018)
Ethel Barrymore (4) - with one win (None But the Lonely Heart (1944)); also nominated for The Spiral Staircase (1946), The Paradine Case (1947), Pinky (1949)
Lee Grant (4) - with one win (Shampoo (1975)); also nominated for Detective Story (1951), The Landlord (1970), Voyage of the Damned (1976)
Maggie Smith (4) - with one win (California Suite (1978)); also nominated for Othello (1965), A Room With a View (1985), Gosford Park (2001)
Maureen Stapleton (4) - with one win (Reds (1981)); also nominated for Lonelyhearts (1958), Airport (1970), Interiors (1978)
Meryl Streep (4) - with one win (Kramer vs. Kramer (1979)); also nominated for The Deer Hunter (1978), Adaptation (2002), and Into the Woods (2014)
Agnes Moorehead (4) - no wins; nominated for The Magnificent Ambersons (1942), Mrs. Parkington (1944), Johnny Belinda (1948), Hush...Hush, Sweet Charlotte (1964)
Geraldine Page (4) - no wins; nominated for Hondo (1953), You're a Big Boy Now (1966), Pete 'n' Tillie (1972), The Pope of Greenwich Village (1984)
Glenn Close (4) - no wins; nominated for The World According to Garp (1982), The Big Chill (1983), The Natural (1984); these three nominations were in consecutive years (1982-1984), and then Hillbilly Elegy (2020)
Shelley Winters (3) - with two wins (The Diary of Anne Frank (1959), A Patch of Blue (1965)); also nominated for The Poseidon Adventure (1972)
Dianne Wiest (3) - with two wins (Hannah and Her Sisters (1986), Bullets Over Broadway (1994)); also nominated for Parenthood (1989)
Anne Revere (3) - with one win (National Velvet (1945)); also nominated for The Song of Bernadette (1943), Gentleman's Agreement (1947)
Celeste Holm (3) - with one win (Gentleman's Agreement (1947)); also nominated for Come to the Stable (1949), All About Eve (1950)
Claire Trevor (3) - with one win (Key Largo (1948)); also nominated for Dead End (1937), The High and the Mighty (1954)
Marisa Tomei (3) - with one win (My Cousin Vinny (1992)); also nominated for In the Bedroom (2001), The Wrestler (2008)
Judi Dench (3) - with one win (Shakespeare in Love (1998)); also nominated for Chocolat (2000) and Belfast (2021)
Cate Blanchett (3) - with one win (The Aviator (2004)); also nominated for Notes on a Scandal (2006), I'm Not There (2007)
Octavia Spencer (3) - with one win (The Help (2011)); also nominated for Hidden Figures (2016) and The Shape of Water (2017)
Gladys Cooper (3) - no wins; nominated for Now, Voyager (1942), The Song of Bernadette (1943), My Fair Lady (1964)
Angela Lansbury (3) - no wins; nominated for Gaslight (1944), The Picture of Dorian Gray (1945), The Manchurian Candidate (1962)
Diane Ladd (3) - no wins; nominated for Alice Doesn't Live Here Anymore (1974), Wild at Heart (1990), Rambling Rose (1991)
Frances McDormand (3) - no wins; nominated for Mississippi Burning (1988), Almost Famous (2000), North Country (2005)
Kathy Bates (3) - no wins; nominated for Primary Colors (1998), About Schmidt (2002), Richard Jewell (2019)
Teresa Wright (2) - with one win (Mrs. Miniver (1942)); also nominated for The Little Foxes (1941) - these two were consecutive nominations