Sutton-in-Ashfield is a market town in the Ashfield district of Nottinghamshire, England, with an estimated population of 48,527 in 2019. It is the largest town in the district of Ashfield, situated four miles west of Mansfield, two miles from the Derbyshire border and 12 miles north of Nottingham.

Sutton-in-Ashfield is home to what was the largest sundial in Europe. It is located in the middle of Portland Square, adjacent to the Idlewells Shopping Centre and Sutton Community Academy. The sundial was unveiled on 29 April 1995.

The former site of Silverhill Colliery, close to the scenic village of Teversal on the north-west edge of Ashfield, has been transformed from the colliery to a woodland, which features several walks for all abilities and also features the highest point in Nottinghamshire. At the highest point stands a monument to all the miners who have worked in the area's coalfields.

King's Mill Hospital is situated between Sutton-in-Ashfield and Mansfield, next to the A38.

The town has an Asda that in April 1999 held the first blessing ceremony and reception to take place in a UK supermarket. It had been unable to get a wedding ceremony licence.

The Sherwood Observatory is located on the B6139 and is run by the Mansfield and Sutton Astronomical Society.