Nigel Alexander Nesbitt is a lawyer and Senior Partner at Darby International sharing many of Louis Litt's specialization fields and characteristics, including his love for cats and mudding. Despite their shared qualities, he does not seem to see eye-to-eye with Louis, due to Louis betraying him. He graduated from Harvard and Cambridge within three years and worked with Dana Scott and Stephen Huntley at Darby International.
In "War", both Nigel and Louis are assigned to make an efficiency list for the merger to see which one is better. Both compete, but when the two manage to talk with each other and share their similarities, they agree to keep each other off their lists so both of them can be kept. Louis, however, puts Nigel on his list when he thinks Nigel would do the same, but Donna reveals that Nigel kept his word and kept Louis out of his. Nigel holds a resentment over Louis after this for "stabbing him in the front".
After being kept out of the list, Nigel manages to come back to the good graces of the law firm and exacts revenge from Louis by tricking him into giving up control over the associates.
When Nigel left for a business trip to their Hong Kong office, he asked Louis to take care of his cat Mikado (in episode "Shadow of a Doubt"). However, Louis hesitated to give the cat back to Nigel (because he felt loss of his cat Bruno) and they arranged mock trial (in episode "She's Mine"). After Louis won, Nigel asked him to get back Mikado in exchange for letting Louis managing associates, which Louis agreed on.
- He has been described as "the British Louis Litt".
- He has cat called Mikado.
- His apartment is on 3291 Belgrave Place, London (according to address wrote on envelopes of Louis Litt's letters sent to Nigel's cat Mikado).
- He graduated Summa Cum Laude from Cambridge and Harvard.
- He attended boarding school from the age of 4 during the time in which his father sent him weekly memos.
- He enjoys mudding.
- He apparently speaks Chinese (Cantonese).