May unexpectedly announced she would seek an early election, saying she needed to strengthen her hand in divorce talks with the European Union by shoring up support for her Brexit plan.
"In terms of Scotland, this move is a huge political miscalculation by the Prime Minister," said Sturgeon, whose Scottish National Party (SNP) is seeking a referendum on independence from the United Kingdom.
"It will once again give people the opportunity to reject the (Conservative government's) narrow, divisive agenda, as well as reinforcing the democratic mandate which already exists for giving the people of Scotland a choice on their future."
Sturgeon has called for an independence vote in late 2018 or early 2019, before Brexit takes effect, but May has rebuffed her calls, saying now was not the time to revisit the independence issue.
The SNP has 54 of Scotland's 59 seats in the United Kingdom's parliament after the last general election in 2015, while the Conservatives have just one.
However, in elections to Scotland's devolved parliament in 2016, the SNP lost seats and fell just short of an overall majority, while the Conservatives made gains.
Sturgeon will hope that a strong showing in the June 8 election will strengthen momentum for her independence plans.
But May could be betting that the election campaign will complicate the SNP's position because polls indicate most Scots do not support a new independence vote. The debate could also expose weaknesses in the SNP's proposals regarding what kind of EU membership Scotland could seek or hope to get after Brexit.
Scots rejected independence in 2014 by a 10-point margin. But they voted to keep their European Union membership last June and Sturgeon says that means Scotland needs a new referendum on secession as it faces a Brexit it did not vote for.
May has refused to discuss the issue until the terms of Brexit have been agreed with the EU -- sometime after the spring of 2019 -- despite Sturgeon last month securing a mandate from the Scottish parliament to seek a new vote.
The leader of the Scottish Conservatives, Ruth Davidson, said the election was a chance to reject the SNP's independence agenda and add to the party's sole seat at the Westminster parliament.
"Only a vote for the Scottish Conservatives will send a strong message that we oppose the SNP's divisive plan for a second referendum," Davidson said in a statement.