The project is in the semi finals of a competition to find the UK's best Lottery-funded scheme.
The monument on Calton Hill was reopened last summer following a restoration project led by the city council, Edinburgh World Heritage and partners as part of the Twelve Monuments Restoration Project, helped by 50,000 of Lottery funding.
Councillor Deidre Brock, the city's culture leader, said: "It's a huge honour for the Nelson Monument and Time Ball to be the only Edinburgh contender in the running for a National Lottery Award, especially so soon after it received a well-deserved four-star rating from VisitScotland.
"Winning the award would be a wonderful tribute to the dedication, hard work and enthusiasm of everyone involved in the Twelve Monuments Restoration Project as well."
It is one of nine Heritage Lottery Fund projects shortlisted for the best heritage project award. The deadline for voting is noon on 18 June. The winner will be announced this summer. To find out how to vote, visit www.lotterygoodcauses.org.uk/awards.