Napoleon Beazley was 17 when he shot and killed John Luttig, 63, as he stole his Mercedes from the driveway of his house in 1994.
Opponents of Beazley's death sentence argued that it was "cruel and unusual punishment" to execute people for crimes they commit as children - and that Beazley's trial was prejudiced because he was black.
In a printed statement released after his execution on Tuesday evening, Beazley apologised for the killing, calling the murder "senseless."
But he also spoke out against his death sentence.
"No one wins tonight. No one gets closure. No one walks away victorious," Beazley wrote.
Amnesty International, South Africa's Archbishop Desmond Tutu, the Council of Europe joined in calls for a review of his case.
Beazley was convicted by an all-white jury, and there have been allegations, all denied, that prosecutors sought the death penalty only because the victim's son is an influential federal appeals judge.
Texas, which executes more people than any other US state, is among five states that allow executions for criminals as young as 17, while another 17 states allow 16-year-olds to face the death penalty.
"I am astounded that Texas and a few other states in the United States take children from their families and execute them," Archbishop Tutu wrote in his submission to the Texas parole board.
Last-ditch attempts
Beazley was pronounced dead at 1817 (2317 GMT) on Tuesday, nine minutes after being injected with lethal drugs at Huntsville prison.
When asked if he had any final words, Beazley looked at his victim's daughter Suzanne Luttig and said: "No".
He had not requested a final meal, prison officials said.
His death came after a day of last-ditch attempts to earn a reprieve.
Texas's parole board voted 10-7 on Tuesday against reducing his sentence to life imprisonment, and 13-4 against a reprieve.
Ambush
At the time of the killing, Beazley had been a popular student and athlete in Grapeland, East Texas, but had also been dealing in drugs for several years.
He was carrying a pistol and had a shotgun in his mother's car when he and two others stalked and then ambushed Mr Luttig and his wife to steal their 10-year-old Mercedes.
Beazley's was the 14th execution in Texas this year. The state carried out a record 40 executions in 2001.
Since the US Supreme Court allowed states to reinstate the death penalty in 1976, 19 people who committed murder under the age of 18 have been executed across the United States, including 11 in Texas.