Mark Allan Isherwood (born 21 January 1959) is a Welsh Conservative Party politician, who has served as a Member of the Senedd (MS) for the North Wales region since 2003.

Isherwood has held a number of Shadow Ministerial positions for the Welsh Conservatives since he was first elected, at various points holding portfolios for Finance, Social Justice, North Wales, Europe, Housing, Communities and Local Government, among others.

[3] In 2001, Isherwood was the Conservative candidate for the constituency of Alyn and Deeside, but was not elected, receiving 26.3% of the vote.

[7] In the 2003 Senedd elections Isherwood ran in the Delyn constituency, where he came second to Welsh Labour's Sandy Mewies.

[14] In 2021 he again ran unsuccessfully for the Delyn constituency, and again came second to Welsh Labour's candidate Hannah Blythyn.

Isherwood further chairs 7 cross party groups - on Autism, Deaf Issues, Disability, Fuel Poverty and Energy Efficiency, Funerals and Bereavement, Hospice and Palliative Care and North Wales.

[17][18] In October 2003, alongside Liberal Democrat Eleanor Burnham, Plaid Cymru's Jocelyn Davies and Welsh Labour's Ann Jones, Isherwood was referred to the South Wales Police for failing to declare on his register of interests that he was employing his wife out of National Assembly funds.

Davies reshuffled the Welsh Conservative front bench, appointing Isherwood as soley Shadow Minister for Communities and Housing.

[31][32] After the 2016 Assembly elections, the Welsh Conservatives were no longer the Official Opposition with 11 seats to Plaid Cymru's 12.

Isherwood was handed briefs on Communities and Europe, being Conservative Party Spokesperson on these matters.

[41] Between March and May 2021 these portfolios again ceased to be shadow ministries, due to Plaid and the Welsh Conservatives being tied for numbers of MSs.

[54] In the debate preceding the vote he cited the possibiliy of coercion and the possibility of disabled people being marked as terminally ill and therefore made eligible, and stated he believed that palliative care ought to be substantially expanded, rather than allowing assisted suicide.