Samuel Atkinson "Sam" Waterston (born November 15, 1940) is an American actor and occasional producer and director. Among other roles, he is noted for his Academy Award-nominated portrayal of Sydney Schanberg in 1984's The Killing Fields, and his Golden Globe- and Screen Actors Guild Award-winning portrayal of Jack McCoy on the NBC television series Law & Order. He has been nominated for multiple Golden Globe-, Screen Actors Guild-, BAFTA- and Emmy Awards, having starred in over eighty film and television productions during his forty-five year career. Allmovie has characterised Waterston as having "cultivated a loyal following with his quietly charismatic, unfailingly solid performances." Description above from the Wikipedia article Sam Waterston, licensed under CC-BY-SA, full list of contributors on Wikipedia.

Sam Waterston plays as Jack McCoy in Grace and Frankie.
Sam Waterston is the top #1 member of the cast and appears in 391 episodes.

Jane Seymour Fonda (born December 21, 1937) is an American actress, political activist, and former fashion model. She is the recipient of various accolades including two Academy Awards, two BAFTA Awards, seven Golden Globe Awards, a Primetime Emmy Award, the AFI Life Achievement Award, and the Honorary Golden Lion. Born to actor Henry Fonda and socialite Frances Ford Seymour, Fonda made her acting debut with the 1960 Broadway play There Was a Little Girl, for which she received a nomination for the Tony Award for Best Featured Actress in a Play, and made her screen debut later the same year with the romantic comedy Tall Story. She rose to prominence in the 1960s with such films as Period of Adjustment (1962), Sunday in New York (1963), Cat Ballou (1965), Barefoot in the Park (1967), and Barbarella (1968). Her first husband was Barbarella director Roger Vadim. A seven-time Academy Award nominee, she received her first nomination for They Shoot Horses, Don't They? (1969), and went on to win the Academy Award for Best Actress twice in the 1970s for Klute (1971) and Coming Home (1978). Her other nominations were for Julia (1977), The China Syndrome (1979), On Golden Pond (1981), and The Morning After (1986). Consecutive hits Fun with Dick and Jane (1977), California Suite (1978), The Electric Horseman (1979), and 9 to 5 (1980) sustained Fonda's box-office drawing power, and she won a Primetime Emmy Award for her performance in the TV film The Dollmaker (1984). Description above from the Wikipedia article Jane Fonda, licensed under CC-BY-SA, full list of contributors on Wikipedia.​

Jane Fonda plays as Grace Hanson in Grace and Frankie.
Jane Fonda is the top #2 member of the cast and appears in 78 episodes.

Mary Jean "Lily" Tomlin (born September 1, 1939) is an American actress, comedian, writer and producer. She has won multiple awards from many quarters, including Tony Awards, Emmy Awards, and a Grammy Award and has also been nominated for an Academy Award.

Lily Tomlin plays as Frankie Bergstein in Grace and Frankie.
Lily Tomlin is the top #3 member of the cast and appears in 78 episodes.

Ramón Gerardo Antonio Estévez  (born August 3, 1940), better known by his stage name Martin Sheen, is a film actor best known for his performances in the films Badlands (1973) and Apocalypse Now (1979), and in the television series The West Wing from 1999 to 2006. In film he has won the Best Actor award at the San Sebastián International Film Festival for his performance as Kit Carruthers in Badlands. His portrayal of Capt. Willard in Apocalypse Now earned a nomination for the BAFTA Award for Best Actor. Sheen has worked with a wide variety of film directors, such as Richard Attenborough, Francis Ford Coppola, Terrence Malick, Mike Nichols, Martin Scorsese, Steven Spielberg and Oliver Stone. He has had a star on the Hollywood Walk of Fame since 1989. In television he has won both a Golden Globe and two Screen Actors Guild awards for playing the lead role of President Bartlet in The West Wing, and an Emmy for guest acting in the sitcom Murphy Brown. Born and raised in the United States to immigrant parents, a first-generation Irish mother, Mary-Anne Phelan from Borrisokane in County Tipperary and a Galician father, Francisco Estévez from Vigo in Galicia (Spain), he adopted the stage name Martin Sheen to help him gain acting parts. He is the father of actors Emilio Estevez, Ramón Estevez, Carlos Irwin Estevez (Charlie Sheen), and Renée Estevez. His younger brother Joe Estevez is also an actor. Although known as an actor, he has also directed one film, Cadence (1990), appearing alongside sons Charlie and Ramon. He has also narrated, produced and directed in documentary television, earning two Daytime Emmy awards in the 1980s. In addition to film and television, Sheen has also become notable for his activism in liberal politics. Description above from the Wikipedia article Martin Sheen, licensed under CC-BY-SA, full list of contributors can be found on Wikipedia.

Martin Sheen plays as Robert Hanson in Grace and Frankie.
Martin Sheen is the top #4 member of the cast and appears in 78 episodes.

Baron Vaughn plays as Nwabudike 'Bud' Bergstein in Grace and Frankie.
Baron Vaughn is the top #5 member of the cast and appears in 78 episodes.

Ethan Embry (real name Ethan Philan Randall) is an American film and television actor.

Ethan Embry plays as Coyote Bergstein in Grace and Frankie.
Ethan Embry is the top #6 member of the cast and appears in 78 episodes.

June Diane Raphael is an American actress, comedian, screenwriter and producer. She starred in TV comedy programs Burning Love and Adult Swim's NTSF:SD:SUV:: and Grace and Frankie. Wikipedia

June Diane Raphael plays as Brianna Hanson in Grace and Frankie.
June Diane Raphael is the top #7 member of the cast and appears in 78 episodes.

Brooklyn Decker is an American film and television actress and former model.

Brooklyn Decker plays as Mallory Hanson in Grace and Frankie.
Brooklyn Decker is the top #8 member of the cast and appears in 78 episodes.