Instead of The Big Bang Theory and How I Met Your Mother, viewers tuning in on 7 May will see "Darren", the man in charge of keeping E4 on air, sitting in the channel's control room.
It is believed to be the first time a UK channel has closed on polling day.
E4 is one of the most popular youth channels on television, reaching 8.7 million 16-34 year olds every month.
Its regular schedule will be suspended from 07:00 BST, when polls open, to 19:00 BST, when the channel will return to normal with Hollyoaks (polling closes at 22:00 BST).
Dan Brooke, Channel 4's chief marketing officer said: "Less than half of under-25s voted at the last election so we've engaged the most powerful weapon that we have at our disposal to try and boost that number - switching off their favourite TV channel for the day."
A pre-election advertising campaign, running on all of Channel 4's stations, will alert viewers to the reason for E4's absence.
The adverts will ask viewers: "How many times have you missed life-changing events because you wanted to watch your favourite show?
"May 7 is election day and Darren is going to turn E4 off so you might as well go and vote. You won't forget will you Darren?"
However, viewers will only be able to use the switch-off as an excuse to vote if they have already registered - and the deadline has already passed.
Meanwhile, Channel 4 will present an "alternative" to the election night coverage on the BBC and ITV, with a programme co-anchored by Jeremy Paxman and comedian David Mitchell.
Paxman, who left BBC Two's Newsnight last June, said: "Elections matter. But that doesn't mean the coverage has to be dull. I hope there'll be room for both insight and laughter."
David Mitchell added: "Our aim is to keep people watching much later than they intended and we will be judged by the dip in the nation's productivity on Friday 8 May."
The show will also include special election-themed episodes of Gogglebox and The Last Leg.
The BBC's coverage of the election will be anchored by David Dimbleby, while Tom Bradby presides over ITV's election show and Adam Boulton anchors Sky's coverage.

The Women into Sustainable Employment scheme aims to improve language and workplace skills and is being piloted in Dundee and Glasgow.
It is run by Bridges Programmes, which supports refugees, asylum seekers and others who do not speak English as a first language.
If successful, the project could be extended across Scotland.
The Scottish government said research suggested women from black and ethnic minority groups face many barriers to work and are under-represented in Scotland's labour market.
Minister for Youth and Women's Employment, Annabelle Ewing, said: "This course is aimed at precisely that group of women and I am very pleased that the Scottish government is able to fund the programme in two of Scotland's cities to help improve their employability, including building up their confidence, sharpen their English language skills and experience the workplace itself.
"We hope that if successful, such an innovative approach to the provision of English for speakers of other languages can be rolled out across Scotland to allow many more to benefit in the future.
"We are committed both to strengthening the economy and reducing inequality in Scotland. Schemes such as Bridges will help us make progress on both fronts by helping a minority group take their rightful place in the workplace."
Founder and director of the Bridges Programmes, Maggie Lennon, said "We are delighted that the Scottish government is funding what we know to be a successful and practical way of getting black and minority ethnic women into work.
"The key to the approach is working closely with employers at every stage, to ensure that the training is relevant to their needs as well as the women, meaning work- placements are more successful which in turn can lead to more sustainable job outcomes.
"Once again we see Scottish employers taking a pro-active role in supporting people far from the workplace."
Channel 4 will shut down E4 on the day of the general election, in a bid to encourage more young people to vote.
[NEXT_CONCEPT]
A new project to help women from ethnic minority backgrounds into work has been given £110,000 of government funding.