From 1295 to 1868, Dorchester was a parliamentary constituency.
This was abolished by the Redistribution of Seats Act 1885, after which Dorchester was placed in the new Dorset South constituency and in 1918 it was transferred to Dorset West, where it has remained ever since.
Dorchester is represented by two tiers of government.
Dorchester Town Council and Dorset Council, both of which are based within the town.
The Member of Parliament for West Dorset was Oliver Letwin from 1997 to 2019.
Since the 2019 general election, the local MP has been Conservative Chris Loder.

The town's coat of arms depicts the old castle that used to stand on the site of the former prison.
The royal purple background represents Dorchester's status as part of the monarch's private estate, a position held since before the Domesday Book was published.
The shield is divided into quarters, two depicting lions and two fleur-de-lis.
These are copied from the shields of the troops from Dorset who took part in the Battle of Agincourt in 1415.
The fleur-de-lis have a scattered arrangement which shows that permission for the armorial bearings was given before 1405, after which date the rights were varied by King Henry VI.
The inscription 'Sigillum Bailivorum Dorcestre' translates as 'Seal of the Bailiffs of Dorchester'.
The mayor has a similar seal of office, but this has the inscription Dorcestriensis Sig: Maioris.

There are four electoral wards in Dorchester (North, South, East and West) showing a combined population of 19,060.
The town has been growing steadily with 11,620 residents in 1951, 13,740 in 1971 and 15,100 in 1991.

On 15 December 2004, Dorchester was the first town in Dorset to be granted Fairtrade status.

In 2011, Dorchester was one of more than 20 towns across the country to apply for city status to mark the Diamond Jubilee of Elizabeth II, although in March 2012 it was revealed that Dorchester's bid had been unsuccessful.
From 1295 to 1868, Dorchester was a parliamentary constituency. This was abolished by the Redistribution of Seats Act 1885, after which Dorchester was placed in the new Dorset South constituency and in 1918 it was transferred to Dorset West, where it has remained ever since. Dorchester is represented by two tiers of government. Dorchester Town Council and Dorset Council, both of which are based within the town. The Member of Parliament for West Dorset was Oliver Letwin from 1997 to 2019. Since the 2019 general election, the local MP has been Conservative Chris Loder.
The town's coat of arms depicts the old castle that used to stand on the site of the former prison. The royal purple background represents Dorchester's status as part of the monarch's private estate, a position held since before the Domesday Book was published. The shield is divided into quarters, two depicting lions and two fleur-de-lis. These are copied from the shields of the troops from Dorset who took part in the Battle of Agincourt in 1415. The fleur-de-lis have a scattered arrangement which shows that permission for the armorial bearings was given before 1405, after which date the rights were varied by King Henry VI. The inscription 'Sigillum Bailivorum Dorcestre' translates as 'Seal of the Bailiffs of Dorchester'. The mayor has a similar seal of office, but this has the inscription Dorcestriensis Sig: Maioris.
There are four electoral wards in Dorchester (North, South, East and West) showing a combined population of 19,060. The town has been growing steadily with 11,620 residents in 1951, 13,740 in 1971 and 15,100 in 1991.
On 15 December 2004, Dorchester was the first town in Dorset to be granted Fairtrade status.
In 2011, Dorchester was one of more than 20 towns across the country to apply for city status to mark the Diamond Jubilee of Elizabeth II, although in March 2012 it was revealed that Dorchester's bid had been unsuccessful.
Dorchester, Dorset