Made stage debut at age four with his father in an amateur production of "Gold in Them Thar Hills" (date approximate)

A sickly child, he underwent three painful ear surgeries before age 10; took up cross-country running with such determination that he eventually broke the New England record for the two-mile

Served as communications officer (ensign) with the US Naval Reserve

Played piano at Old Nick Saloon in New York City

Performed with New England stock company on radio and in Off-Broadway productions; produced and acted in three short-lived TV series with first wife Cynthia Stone ("That Wonderful Guy" ABC, 1950; "Ad Libbers" CBS, 1951; "Heaven for Betsy" CBS, 1952)

Founded Jalem Production Company

Broadway debut as Leo Davis in "Room Service"

Film acting debut in "It Should Happen to You", directed by George Cukor

First of six films with director Richard Quine, "My Sister Eileen" (screenplay by Quine and Blake Edwards); had actually done a film with Quine ("Extra Dollars") the year before for the United States Treasury Department

Won Oscar as Best Supporting Actor for his portrayal of Ensign Pulver in his fourth movie, "Mister Roberts"

Acted in "Fire Down Below" and received credit as a song performer for the harmonica theme

First film with director Billy Wilder, "Some Like It Hot"; received first Best Actor Academy Award nomination

Attempted to climb corporate ladder by loaning his apartment key to various executives for their trysts in Wilder's "The Apartment"; earned a Best Actor Oscar nomination

Appeared as Lee Remick's husband who pulls her into alcoholism in Blake Edwards' "Days of Wine and Roses", his first major dramatic film role; garnered another Best Actor Academy Award nomination

Last film with Quine, "How to Murder Your Wife"

Reteamed with Edwards for "The Great Race"

First film opposite Walter Matthau, "The Fortune Cookie"

Executive produced "Cool Hand Luke", starring Paul Newman

Reteamed with Matthau for their definitive vehicle, Neil Simon's "The Odd Couple"

Starred opposite Sandy Dennis in "The Out of Towners", scripted by Simon

Directed feature film "Kotch", starring Matthau and Lemmon's second wife Felicia Farr

Hosted the acclaimed NBC variety special "Jack Lemmon in 'S Wonderful, 'S Marvelous, 'S Gershwin"; received Emmy Award

Received a Golden Globe Award for his comic performance in Wilder's underrated "Avanti!"

Won second Oscar as Best Actor for his down and out salesman in "Save the Tiger"

Played Archie Rice in NBC TV version of John Osborne's "The Entertainer" at the urging of Laurence Olivier, who had created the role on stage and film; received Emmy nomination

Created the role of Scottie Templeton in Broadway production of Bernard Slade's "Tribute"; reprised part in 1980 film version for which he earned an Oscar nomination and also co-wrote the song "It's All for the Best" with Alan Jay Lerner; reteamed with Remick in film

Starred as dedicated plant executive in "The China Syndrome", a heartpounding drama about an attempted cover-up of an accident at California nuclear plant; nominated for a Best Actor Academy Award

Wrote screenplay for "Track Two", a documentary feature

Starred with Matthau in seventh and last film with Wilder, "Buddy Buddy"; also Wilder's last film

Portrayed stiff-backed Ed Horman searching for his missing son in Costa-Gavras' "Missing"; again garnered a Best Actor Oscar nomination

Returned to Broadway as James Tyrone in revival of Eugene O'Neill's "Long Day's Journey Into Night"; reprised role for 1987 Showtime TV version; first association with actor Kevin Spacey and Peter Gallagher

Inducted into Television Academy Hall of Fame

Reunited with Spacey and Gallagher in the NBC miniseries "The Murder of Mary Phagan"

Appeared in title role of "Dad", co-starring Spacey

Delivered a nice turn as private investigator Jack Martin in Oliver Stone's "JFK"

Offered totally credible turn as the loser in an office full of desperate real estate salesmen in "Glengarry Glen Ross"; Spacey also in cast

Scored huge commercial success with Matthau in "Grumpy Old Men"

Sequel "Grumpier Old Men" proved an even bigger hit than its precursor

Directed by Matthau's son Charles in "The Grass Harp", adapted from the Truman Capote book

Ninth feature with Matthau, "Out to Sea"

Played Juror 8 in TV remake of "12 Angry Men" (Showtime); ensemble cast included Goerge C Scott

Reteamed with Simon and Matthau for "The Odd Couple II"; tenth feature collaboration with Matthau

Portrayed Henry Drummond to Scott's Matthew Harrison Brady in the Showtime remake of "Inherit the Wind"; Scott a few years prior had played Drummond to Charles Durning's Brady on Broadway

Played Morrie Schwartz in "Tuesdays with Morrie", an ABC movie executive produced by Oprah Winfrey; garnered Emmy Award

Appeared in cameo and served as narrator of "The Legend of Bagger Vance"