Recently, world-renowned actor Simon Callow helped celebrate the occaision with the Annual Lyric Lecture.
Fresh from his run in The Man Jesus, Callow described the Lyric as 'one of the most beautiful new theatres in Europe.'
Since it was rebuilt in 2011 there have been 882 performances of 108 productions in the new theatre across its two stages.
The building itself has won 18 architectural and theatre awards, including reaching the final six shortlist for the prestigious Stirling Prize last autumn.
Lyric Chief Executive Ciaran McAuley said he was 'delighted' the new theatre is welcoming so many new audiences.
It's hard to believe the new building has been open two years on 1 May.
Richard Croxford, Lyric Artistic Director
"We have achieved this through an exciting combination of first rate Lyric productions alongside the best of visiting companies, and a range of comedy and music events, and quality family entertainment," he said.
"As we celebrate our second anniversary, we would like to thank all those who have contributed to our success so far - our hard-working staff, actors and creative teams, funders and sponsors, the media, and our audiences."
Lyric Artistic Director, Richard Croxford added: "We are delighted with the support we have had from audiences to our exciting and varied programme and look forward to that continuing in the years to come.
"The new building is only two years old but Belfast as a city is celebrating 400 years and we have enjoyed a wonderful season commemorating this with our Tales of the City plays which continue this month.