The 21-year-old came through the age grade system with the Liberty Stadium side and became the youngest player to feature in a RaboDirect PRO12 game when he made his debut aged 17 years and 222 days in a November 2007 defeat to Leinster.
Beck has established himself as a first-team regular so far this term, and scored his first Heineken Cup tries as he grabbed a brace in an impressive individual display in Saturday's defeat to Saracens at Wembley.
Beck said: "It's great that I've been able to secure a new contract. I've been fortunate enough to get some valuable first-team experience this year and for the coaches to think I've performed well enough to get another two years is fantastic.
"I'm really excited about the future of the Ospreys. We've got a young squad here and we've done really well as a team this season. We are developing well and I think that we can get better still.
"Working with the great players and coaches here has really helped me kick on as a player and I'm enjoying representing my home region.
"I genuinely believe that if we keep working hard and keep improving then we can do the region proud."