The S&P 500 and tech-heavy Nasdaq also achieved new highs, fuelled by hopes that President Donald Trump’s policies will boost the US economy, reports The BBC.
The Dow, which has nudged the 20,000 milestone during January, rose 0.8 per cent to 20,068.51.
Investors’ cash has poured into shares on hopes of tax cuts and higher growth.
The Dow had risen above 20,000 early into the trading day, prompting Mr Trump’s senior adviser Kellyanne Conway to tweet that the landmark was down to “The Trump Effect”.
“It was definitely a milestone that the market has been focused on for really the better part of two months and you were starting to get a little bit of anxiety as to whether it was going to be surmounted or not,” said Julian Emanuel, Equity Strategist at UBS.
The Dow reached its latest 1,000-point milestone two months after closing above 19,000, making it the second quickest 1,000 point rise ever.
The index rose from 10,000 to 11,000 in only 24 trading days between 29 March and 3 May, 1999, while the rise from 18,000 to 19,000 took 483 trading days (nearly two years).
Financial stocks have been a major factor in the gain – with Goldman Sachs and JPMorgan accounting for around 20% of the rise.
This is because investors believe that some of Mr Trump’s policies will trigger inflation and produce a rise in interest rates.
Also on Wednesday, the broad-based S&P finished up 0.8 per cent at 2,298.37, while the Nasdaq advanced 1 per cent to 5,656.34 – both fresh records.
