Lee Ann De La Vega
Occupation: Owner of De La Vega Oil
Owner of Ewing Oil
Marital status: Widow
Spouse(s): Roberto De La Vega (deceased)
Other Relationships: J.R. Ewing (early 60's, briefly 1991)
Played by: Barbara Eden
Appears on: Dallas (first series)

Lee Ann De La Vega (nee Nelson) is a South American entrepreneur and a woman from J.R. Ewing's past who came back from revenge. She is the daughter of a Baptist schoolteacher. She met J.R. at the University of Texas and became pregnant by him, later having an abortion that left her unable to have children.

She later married Venezuelan oil man Roberto De La Vega and later, inherited his company, De La Vega Oil. In 1991, she bought Ewing Oil from Bobby Ewing and the company became a wholly-owned subsidiary of De La Vega Oil. She taunted J.R. by letting him remain at Ewing Oil and managed to end J.R.'s relationship with Vanessa Beaumont by seducing J.R. Having her revenge against J.R., Lee Ann left Dallas and sold Ewing Oil to Michelle Stevens.