Initially gathering under the name of the 'Hills Christian Life Centre' in August 1983, Hillsong church began as a congregation of around 45 in the hall of Baulkham Hills Public School.
Today, the Pentecostal megachurch has expanded across the globe into major cities including London, Cape Town, Kiev and New York.
"Bobbie and I are overwhelmed with all God has done in the 30 years since as a 29 & 26 year old, we planted Hillsong Church," Brian Houston wrote via Facebook.
"We are overwhelmed with all the love we are receiving."
Bobbie Houston also took to social media to celebrate the milestone.
"30 years ago I followed [Brian] into the biggest adventure of our lives - planting a church in Sydney's [northwest]," she wrote.
"[It] hasn't always been plain sailing but His grace has overshadowed our lives every inch of the way."
Well wishes and messages of appreciation flooded in for the Houstons:
"30yrs ago today a young couple started a church that has millions saying THANK YOU! We love you," wrote lead pastor of Hillsong Australia, Joel A'Bell.
"Thanking God today for our pastors @BrianCHouston & @bobbiehouston for planting @hillsong church 30 years ago. Forever grateful ‪#‎thanksfor30‬," Christine Caine tweeted.
"30 years ago TODAY, Brian Houston & Bobbie Houston took a step of faith & started Hills CLC, better known now as Hillsong Church. 40 or so people in a small school hall. We are here because you were there," Joel Houston wrote.
"Much love and appreciation to @briancharleshouston @rlhouston !!! Thank you for your love and leadership. My family is so blessed to be a part of our Church," wrote Hillsong musician Matt Crocker.
"30 years ago TODAY Pastor Brian & Bobbie Houston planted ‪#‎Hillsong‬ Church! Their Passion for Jesus and Faithfulness has enabled thousands to encounter Christ and find HOME! THANK YOU!" wrote Hillsong Asian & Filipino Service.