THE NATIONAL Gallery of Art continues its free "Country House on Film" series this weekend with Alfred Hitchcock's four-star 1940 smash, Rebecca, starring Laurence Olivier, Joan Fontaine, George Sanders and Nigel Bruce. The film, which won Academy Awards for Best Picture and Cinematography (George Barnes), screens Friday and Saturday at 2:30 and Sunday at 6 in the East Building Auditorium.

Next weekend, see The Uninvited (1944) and Kitty (1945) at the same times. The Importance of Being Earnest (1952) and Blithe Spirit (1945) wind up the series on February 21 and 22. For details, call 737-4215.

Catherine Deneuve and Philippe Noiret star in L'Africain, which opens the two-week French Film Festival Friday at the K-B Janus. The series of seven films, all recent eleases, runs through February 20, with each movie showing for two days. Scheduled are Tout Feu Tout Flamme; Hotel Des Am,eriques; Barocco; Malevil; Rive Droite, Rive Gauche; and Le Bon Plaisir. Normal prices are in effect for the festival at the theater, 1660 Connecticut Avenue NW. Call 232-8900 for a schedule.

The Italian Film Festival at the American University continues this Sunday at 7 with free screenings of two Ermano Olmi flicks, Cammina, Cammina and L'Albero degli Zoccoli. There is one catch: The pictures are in Italian and there are no subtitles. The program is in the Wechsler Theater. Call 885- 2040.

Meanwhile, American University's film schedule of freebies at the Mary Graydon Center looks good for each evening next week beginning with Monday's The Bicycle Thief and The Golddiggers and ending on Thursday with perhaps the greatest propaganda film of all time, Triumph of the Will, the 1935 documentary of Adolf Hitler's Nuremberg rallies in 1934. This 110-minute movie is both fascinating and frightening. Again, call 885-2040.

The National Air and Space Museum has announced a major collaboration with the University of South Carolina to transfer to safety film more than 800,000 feet of vintage Movietone newsreel footage made of "almost every major aviation event and personality of the 1920s." The estimated cost of saving these rare films, which are stored on "rapidly deteriorating nitrate stock," has been set at $550,000.

If you missed Claude Lanzman's Holocaust documentary Shoah last month at the Key Theater, the Jewish Community Center of Greater Washington is offering a two-week make-up session. Beginning on Monday at 9 a.m., you can catch the 41/2-hour Part I for $10. Part II, also 41/2 hours and also $10, first screens Wednesday at 6:30. Screenings are scheduled through February 23. For showtimes, call 881-0100.

Don't forget that there's still time to enter "Expose Yourself," the Biograph's annual showcase for local filmmakers working in 16mm. The entry deadline is March 4, with screenings on March 12 and 13 at the Georgetown movie house. Call 338-0707.

In Baltimore, the Film Forum has extended the deadline to February 10 for accepting applications and entry fees for the 17th Annual Independent Filmmakers' Competition, sponsored by the Baltimore International Film Festival. The Forum must have the 16mm film by February 15. For details, call 301/685-4170.

The Film Forum's ongoing salute to the late Orson Welles offers The Lady From Shanghai (1948), starring Welles and Rita Hayworth, on Thursday. The series continues on the remaining Thursday nights of February. On February 20 it's Touch of Evil. And on February 27, it's Chimes at Midnight, his adaptation of Shakespeare's Falstaff plays. "Chimes," made in 1967, stars Jeanne Moreau, John Gielgud and Margaret Rutherford. Reels roll at 8 at 516 North Charles Street in Baltimore. Admission is $3.50 for the general public; $2.50 for Film Forum and Baltimore Museum of Art members. Call 301/685-4170.

The Smithsonian Resident Associate Program will also dip into Welles' work with a similar program designed to honor the filmmaker. It begins February 24 with his masterful 1942 black-and-white follow-up to "Citizen Kane," The Magnificent Ambersons, based on the novel by Booth Tarkington and starring Joseph Cotten, Anne Baxter and Agnes Moorhead. The six-movie series will run Monday evenings through March in the American History Museum's Carmichael Auditorium. Call 357-3030 for information.

Last week's light snow forced the Resident Associates to postpone their screeening of the 1983 Indian film, Adi Shankaracharya, or "The Philosopher." It has been rescheduled for Tuesday at 7:30 in Carmichael Auditorium. Cost is $4 for members; $6.50 non-members. Again, call 357-3030.

The Resident Associate Program's salute to "Black History Month" concludes Thursday evening at 6 in Carmichael Auditorium with Blood of Jesus, a 1941 drama starring Spencer Williams, who also wrote and directed. Cost is $4 for members; $5.50 non-members.

The free "America on Film" series on Wednesdays at noon at the American History Museum offers an impressive schedule of music-oriented movies for February. This coming Wednesday it's Lady Be Good, starring Ann Sothern, Robert Young and Eleanor Powell and featuring the songs of Jerome Kern and George Gershwin. On February 19, it's Rhapsody in Blue, from 1945, with Robert Alda starring as George Gershwin; and on February 26, the film is Words and Music, with Richard Rodgers and Lorenz Hart compositions. It stars Judy Garland, Mickey Rooney and Gene Kelly. The screenings are in Carmichael Auditorium.

SHORT SUBJECTS -- George Lucas' 1980 blockbuster sequel to "Star Wars," The Empire Strikes Back, will be shown Friday and Saturday evenings at 7:30 in the Air & Space Museum's Langley Theater. It's free. Call 357-1400 for a schedule of additional screenings.

The Northern Virginia Community College film watchers series screens the German- made Chronicle of Anna Magdalena Bach for free, Friday at 8 at the Alexandria campus' Bisdorf Building, Room 110. Call 845-6207.

Simone Signoret and Yves Montand star in Wednesday evening's 7:30 screening of Le Joli Mai at George Mason University's Lecture Hall No. 1. Call 323-2220.

Baltimore's Walters Art Gallery celebrates "Black History Month" with a Wednesday evening series. This coming Wednesday is double-feature night, presenting The Emperor Jones (1935) with Paul Robeson, and The Angel That Stands by Me. All screenings are free and begin at 8 at 600 North Charles Street. 301/547-ARTS.

The Renwick Gallery offers Painting in an Empty Land, a look at the relationship of New Zealand's light and land to art through the works of four painters, on Thursday at 11, noon and 1. It's free.

The Martin Luther King Library's "Black History" celebration winds up Thursday beginning at 6 p.m. with the 1937 God's Stepchildren and followed by Let My People Live (1939). The latter was recently transferred from nitrate film stock. Film historians Pearl Bowser and Jan-Christopher Horak will be on hand for a discussion following the showings. Call 727-1271.

HISTORICALLY SPEAKING -- Friday marks the day in 1964 when the Beatles, after landing in New York's Kennedy Airport, launched the British Invasion, which also led to the group's three movies, A Hard Day's Night in 1964, Help! the following year, and the animated Yellow Submarine in 1968. Friday is also actor Eddie Bracken's 66th birthday. Saturday marks the day in 1915 that D.W. Griffith's The Birth of a Nation premiered at Clune's Auditorium in Los Angeles. Actress Lana Turner celebrates her 66th birthday on Saturday; Jack Lemmon is 61; Alejandro Rey, 56; ABC News anchor Ted Koppel, 46; Nick Nolte, 45; Brooke Adams, 37; and Gary Coleman, 18. Actress Mia Farrow is 41 Sunday.