Bolton based Leighs employs 260 staff and also has operations in Germany, Canada, India and the Middle East.
The deal was confirmed today bringing to an end more than 150 years of ownership by the Leigh family.
Brian Leigh-Bramwell, Chairman of Leighs Paints, said: “This outstanding company has been a part of my family for the past 151 years.
“I am confident this decision will be of great benefit to both companies and our customers well into the future.”
Sherwin-Williams specialises in the manufacture, development, distribution, and sale of coatings and related products to professional, industrial, commercial and retail customers.
It is America’s largest paint firm and number three in the world with a turnover of £4.8bn.
Chris Connor, Chairman and CEO of the Sherwin-Williams Company, said: “We are very pleased to bring Leighs Paints, a well-respected company, and their employees into the Sherwin-Williams family.
“Combined, our two companies have nearly three centuries of experience in coatings innovation.
“This is another positive step in our strategy of steady growth and expansion through quality products and people who provide excellent customer service. This acquisition reaffirms our strategic commitment to growing globally.”