LeBron James had previously been the youngest to get a triple-double, doing so in the 2004-05 season at 20 years, 20 days.
Ball completed his triple-double when he grabbed his 10th rebound early in the fourth quarter. He also had 13 points and 11 assists at the time.
Ball finished with 19 points, 13 assists and 12 rebounds, and had 3 steals and a career-high-tying 4 blocks. Afterward, Ball said the triple-double didn't mean anything, because the Lakers lost 98-90, their third straight defeat.
"I really don't care," Ball said of the personal feat. "We took a loss. It don't really mean nothing."
It's perhaps fitting that Ball collected his first triple-double in his first game against the Bucks, whose coach, Jason Kidd, ranked third all time in triple-doubles with 107, behind only Oscar Robertson and Magic Johnson. Ball has often been compared to Kidd because of his passing, vision, rebounding ability and overall game that make him well-suited to produce triple-doubles.
Ball, playing in his 13th career game, got his first triple-double much quicker than Kidd, who needed 68 games to get his firs
"That's going to be, I guess, the headline, that he got a triple-double and I got to see it in the front row," said Kidd, who on Friday said it was "a stretch" to compare Ball to him because it's too early in Ball's career. "Ball can play, and he is going to make his teammates and team better. Triple-double, that is going to be the norm for him. He is going to fill up the stat sheets.
"But we just got to give him time. We are trying to put him in a microwave and speed him up. He is going to make mistakes and he is going to have bad nights, but he competes and he is going to find a way to win."
It took Ball just 15 minutes to reach a double-double Saturday with 11 points and 10 assists. He had six rebounds by halftime and nine by the time he went to the bench for a rest late in the third quarter.
Ball clinched the triple-double with a rebound with 11:39 left in the fourth quarter after Milwaukee's Thon Maker shot an air ball into Ball's hands.
Ball, who entered Saturday shooting just 29.2 percent from the field and 22 percent from 3-point range, hit 7-of-12 from the field Saturday night, including 3-of-5 from the 3-point line, representing his best shooting game since he was 6-of-13 in a win over Detroit on Oct. 31.
"Just came out aggressive," Ball said. "I told you, I am going to keep shooting."
In July, Johnson, now the Lakers' team president, predicted that Ball would be getting multiple triple-doubles as a rookie, after seeing the No. 2 overall pick become the first rookie to get a triple-double in the Las Vegas Summer League.
"You can see that," Johnson said of Ball, who finished with two triple-doubles in summer league. "If he's getting triple-doubles in the summer league, he is going to get triple-doubles in the regular season. Just like me, when I got here, there was pressure. I was the No. 1 pick [in 1979]. I didn't care about that. I am going to play my game. Lonzo is going to play his game. The great ones do."
Ball said he was "just grateful" that some were comparing him to Kidd, who was an NBA champion, a 10-time All-Star, five-time first-team All-NBA performer, five-time assists leader, three-time All-Defensive selection and co-Rookie of the Year in 1994-95.