When I was in my 20s I went through a bit of a classic movie phase and Katharine was a big part of that. I think the first movie I saw her in was Sylvia Scarlett (1935) where she pretended to be a boy. It was a good indication that she did things her own way. She is smart and funny and quick as a whip. I love how she challenged norms and stayed true to herself.
She was born in 1907 Connecticut to a doctor and a suffragette. One of her brothers committed suicide in his teens and it affected her greatly. Even though she had a house in NYC and rented in LA when she filmed there, she consider Connecticut her lifelong home. She was married, but it didn’t work out and the married Spencer Tracy became the love of her life.
She is the only actress to have 4 Oscars.
I recently watched Call Me Kate on Netflix and it’s fantastic if you’re a fan. I also read The Private World of Katharine Hepburn by John Bryson and loved it! You can check it out here.
These are the movies I remember watching.
The A movies
The Philadelphia Story (1940) is one of my all-time faves, also starring Cary Grant and Jimmy Stewart. A perfect romantic comedy.
State of the Union (1948) also starring Spencer Tracy and Van Johnson. It is amazing how little has changed in politics in 75 years!
Desk Set (1957) also starring Spencer Tracy. An office romance.
Bringing Up Baby (1938) also starring Cary Grant. A goofball of a romantic comedy.
The African Queen (1951) also starring Humphrey Bogart. A sailing adventure!
On Golden Pond (1981) also starring Henry Fonda and Jane Fonda. Henry and Katharine both won Oscars for their performances.
The B movies
Guess Who’s Coming to Dinner (1967) also starring Spencer Tracy, Sidney Poitier and Katherine’s niece, Katharine Houghton. Interracial relationships served.
Holiday (1938) also starring Cary Grant. Her sister gets the man, sort of.
The Lion in Winter (1968) also starring Peter O’Toole. Henry II has a choice to make.
The B-/C+ movies
Summertime (1955) Venice is my favorite city so I loved that this showed the romance of the place.
Sylvia Scarlett (1935) also starring Cary Grant. Gender swapping hijinks.
See my other Top 100 Actors here.
Stacy's Books 
Katherine Hepburn is one of my favorite actors also. I have seen all of her films including Alice Adams and Christopher Strong. Kate was a rare talent who was successful on the stage and in film. I have taught 3 courses at ILR East about Kate. I also gave a class on Tracy and Hepburn. I disagree with one of your choices. I would move Desk Set down with the B movies and move The Lion in Winter into the list of A pictures. Lion is a 2 hour master class in movie acting. I have seen Lion more times than any other Hepburn movie with the exception of Woman of the Year.
I think I need to take one of your classes Bill! Tell me what you’re teaching next!
Loved the movies she made with Humphrey Bogart.
Yes! I think there is one or two I haven’t seen yet, but I want too!