The move follows last month's referendum on independence in Scotland when voters aged 16 and above were allowed to cast their ballots and proposals in Britain for the voting age in future general elections to be lowered.
"With the referendum in Scotland having included 16-year-old voters, any future referenda in the UK and Gibraltar are likely to have such a franchise," Gibraltar Chief Minister Fabian Picardo said in a statement.
"As a result, it is clear to us that voting at general elections should also be extended to those who are 16 years and over.
"The 16-year-olds who I know are responsible young adults who know what they want and what they stand for. They have a lot to contribute and their voice should be heard at election time."
Picardo's Socialist-Liberal alliance holds 10 out of the 17 seats in Gibraltar's assembly, meaning the proposal is virtually assured of passing.
If it is approved, Gibraltar will become one of a handful of territories or nations with a voting age of just 16, joining Austria, Brazil, Cuba and Nicaragua.
The next elections in Gibraltar, an enclave of 30,000 people that occupies a strategic spot at the western neck of the Mediterranean, are due by April 2016.
Spain ceded Gibraltar to Britain in 1713 under the Treaty of Utrecht. But Madrid has long argued that it should be returned to Spanish sovereignty. Britain refuses to hand it back against the wishes of Gibraltarians.
Nearly 99 per cent of the population rejected sharing sovereignty with Spain in a November 2002 referendum.
Gibraltar is self-governing in internal affairs, with Britain responsible mainly for defence and foreign affairs.