Speaking to the County Press outside Medina Leisure Centre, where the count took place, he thanked council staff and party colleagues and said he had been 'fortunate' to have had the opportunity to lead the local authority.
The Conservative lost to The Green Party's Claire Critchison, in a head-to-head race, after an overall Isle of Wight turnout of just over 36 per cent, on Thursday, May 6.
Mr Stewart won 636 votes, to Cllr Critchison's 876.
This year, she overturned her 2017 deficit (Dave Stewart: 791 votes; Claire Critchison: 313 votes; Wendy Loader (Labour): 80 votes, in 2017) to swing the rural West Wight seat from blue, to green.