The event is being organised by Lost Arts, a body set up by eight trade unions, including Prospect, whose 5,000 specialist members in the heritage sector are directly affected by cuts to the arts.
Following the human chain, activities will continue with an evening of speakers, poetry and music at the 12 Bar Club from 7pm.
Since 2010, the budget of the Department for Culture, Media and Sport (DCMS) has been cut by over a third. At the same time, spending by local government on arts and culture has also been cut by £124 million.
As a result there has been a significant reduction in subsidies and grants to cultural bodies, staff cuts, reduced access for the public and even closures.
Prospect national secretary, Alan Leighton, said: “The creative industries employ 2.5 million people in the UK and accounts for at least £865m of tourist spending every year.
“Even so, the government is continuing to slash budgets for organisations like our national museums and galleries and other heritage organisations, and fails to recognise the true value, contribution and importance of access to arts and culture.”
Members, and the public, can show their support for the arts by joining the human chain or using the hashtag #LinkUpForArt.
The 12 Bar Club is at 26 Denmark St, London, WC2H 8NJ. Tickets, for an evening of music and live entertainment, are £5 per person and will be available on the door.