The 38-year-old Colombian star, who is best known for playing Gloria in Modern Family, said that she got a similar tattoo to Ledger after working with him in skateboarding movie Lords Of Dogtown in 2005.
Vergara told The Daily Telegraph: "We had a lot of conversations while we were on the set and during makeup and I got an idea from him. He had a tattoo on his wrist of his sisters' names and after I talked to him I did a tattoo of my brother's name who passed away."
Ledger had the initials K, A, O and S on his left wrist for his sisters Kate, Ashleigh and Olivia and his mother Sally.
Vergara also revealed that she remembers being in New York when she heard of Ledger's death from an accidental overdose of prescription medication in 2008.
The actress's brother Rafael was shot dead in their home country during a kidnap attempt in 1998. As a result, she fled the country with her mother, son and sister. She said that since losing her sibling, she doesn't "sweat the small stuff".