The 26-year-old from Galway, who is equally adept in the second row or back row, has featured regularly in both positions this season after enduring a frustrating season last term through injury.
A torn Achilles tendon kept him out for all of last year, but he has recovered fully to feature regularly in the Connacht pack this season.
His versatility and attributes in both set piece and open play have seen him develop into a key member of the westerners' squad.
Connacht Chief Executive Tom Sears said: "Andrew has been top quality this season after coming back from serious injury.
"His ability to cover a number of positions is a real asset and he has put in consistently high performances this year in whichever role he has been asked to fill.
"The coaching staff are delighted with his form this season and believe there is more to come from him in the future as his game continues to develop.
"As a locally-born player he has a real affinity to Connacht Rugby and we see the qualities in him to become a vital member of the squad for years to come."