Who is a famous character or person who is like Portia in The Merchant of Venice and how are they like them?
I think that Portia is someone who is notable for the fact that A) she is very intelligent and forceful and deserves to have success in life but B) her life is controlled by forces outside her control -- the patriarchy that keeps her in her "place."
I'd compare her to Eleanor Roosevelt (since I'm a historian/political science type). I see them as very talented people whose ability to fully realize their potential was curtailed by their societies.
This is a very interesting question that you would benefit from adding to the discussion board to gain a range of different opinions rather than just mine. A good way of starting considering this question is to think about Portia's mix of characteristics. She is a strange mix of contrasting features. She is (reluctantly) obedient to her dead father's wishes, and yet she shows herself to be independent and active in her ability to help her husband get his best friend out of trouble. She is clearly intelligent and able to think on her feet and she has a great sense of humour.
I must admit, I kind of relate her to Lizzie Bennet in Jane Austen's Pride and Prejudice. Both show a fierce independent spark but Lizzie likewise acts within the confines of expected behaviour of a daughter of that time. You might want to see if you can take this comparison further.
A character Shakespeare may have had in mind is Athena, goddess of wisdom and the arts in Greek Mythology, more specifically the conclusion of the ODYSSEY. The last line of Robert Fitzgerald's translation reads: "though still she kept the form and voice of Mentor." The last line of the first conversation in MV reads: "though Nestor swear the jest be laughable"(1.1.156). In the scene which immediately precedes the court scene is mention of Scylla and Charybdis which Professor Bevington identified as "twin dangers in the ODYSSEY, 12.255." Portia and Penelope are both besieged by suitors.