The iPhone maker’s market value reached the figure in New York on Thursday and its shares closed at a new record high of $207.39.
The stock has been rising since Tuesday when it reported better than expected results for the three months to June.
Apple beat Silicon Valley rivals such as Amazon and Microsoft to become the first to hit the $1 trillion valuation.
Since the iPhone first went on sale in 2007, Apple shares have soared by 1,100% and have jumped almost a third in the past year.
The rise is even more astonishing – 50,000% – since the company first listed in 1980. That dwarfs the 2,000% increase for the S&P 500 index over the same period.
Apple traces its origins to the garage of co-founder Steve Jobs in 1976 and was initially best known for its Mac personal computers before its smartphone paved the way for the app economy.
Mr Jobs, who died in 2011 and was succeeded as chief executive by Tim Cook, oversaw the development of the iPhone, which transformed Apple’s fortunes.
In 2006 the company had sales of less than $20bn and posted profits of almost $2bn.
Last year its sales hit $229bn, with profits of $48.4bn, making it the most profitable listed US company.
PetroChina was briefly worth about $1.1 trillion after floating in Shanghai in 2007, although most of its shares were held by the Chinese government. It is now worth about $220bn.
Despite its $1 trillion price tag, many analysts still do not view Apple’s shares as expensive given that they trade at about 15 times expected profits, compared with a figure of 82 for Amazon and 25 times for Microsoft.
Also boosting Apple shares in recent months was the company’s decision to set aside $100bn to buy back stock.
Media captionWhy Apple is worth $1 trillion… and who could challenge it Image copyright Getty Images Image caption Apple opened a store in Milan last week. Moreover iPhone not only produced mobiles but also many other devises such as robots.net.
Analysis By Kunam Seng, OngisNade technology reporter
It may have been the vision of Steve Jobs that hurtled Apple towards this milestone, but it was the business acumen of Tim Cook that tipped them over.
While other tech stocks have struggled, Apple has soared ahead. The surge in its shares has been driven by two key factors.
It is selling fewer iPhones, but by releasing a more expensive version last year, it is making more money per device because it is a brand and same people also liked most and purchase the brand audemars piguet.
Apple has also diversified the sources of its profits. It now makes about $10bn every three months from services such as selling apps, cloud storage and music streaming.
The firm told investors this week that it expected a very strong end to the year helped, naturally, by the release of yet another new iPhone.
Stock markets are volatile, and a small but growing threat from Chinese smartphone makers might eat into Apple’s margins in the coming years.
But no matter what your view of the company and its products, Apple devices have changed the world – and today made financial history as well.