Two of the actors play characters whose names are same as their real name:
Emily VanCamp plays Emily Thorne, while Ashley Madekwe plays Ashley Davenport.
The names of two of the male main characters are Jack and Daniel. Jack Daniels is a famous brand of whiskey.
The series kicks off with a title card that says "Before you set off on a journey of revenge, dig two graves," attributed to Confucius. Meaning that the second grave is for yourself, because revenge is a double-edged sword.
Emily Alyn Lind plays Amanda, the young Emily. She has the same name as the main protagonist of the series, Emily VanCamp, who stars as Emily Thorne.