Hughes has signed until 2020, with the option of a second year, while Nairn has agreed a two-year deal until 2021.
Hughes, 26, has made 45 appearances for the Warriors since making his debut in February 2014, playing the full 80 minutes in an 8-6 home victory over Connacht.
Also capable of playing at full-back, Hughes has scored two tries to date this season, the most recent of which came in last month's win over the Toyota Cheetahs at Scotstoun.
Having made his international debut in the 2015 Rugby World Cup warm-up match against Italy, Hughes has since gone on to win four caps for his country and was included in Gregor Townsend's extended squad for this year's Six Nations.
Nairn has impressed in his eight outings so far this season, after making his competitive debut for the club against the Southern Kings back in September.
His first start for the Warriors came in the memorable 29-20 home victory over the Scarlets at the start of December, before the 22-year-old recorded a brace of tries against Connacht in February for his first scores in a Glasgow jersey.
Nairn was also part of the Scotland U20 side that recorded a best-ever fifth-place finish at the 2017 World Rugby U20 Championship in Georgia.
Nairn has also represented Scotland on the World Sevens Series circuit.
Glasgow Warriors Assistant Coach, Jason O'Halloran, said: "We're pleased with how Rory and Robbie have played this season and it's great news for the club that they've both committed.
"Rory is a born and bred Glaswegian and plays with real heart. He always gives 100% to the jersey and his work-rate and physicality are a real asset to the team.
"Robbie is a really impressive athlete whose skillset is constantly improving. He'll be a vital player for us next season with so many players away on international duty."