The show picked up the scripted comedy award and comedy writer prize for creator Phoebe Waller-Bridge.
Chernobyl writer Craig Mazin took the drama prize, while Channel 5 was named channel of the year.
RuPaul’s Drag Race UK, the English spin-off of the hit reality series, was named best entertainment show, while Gentleman Jack was best drama series.
Saoirse-Monica Jackson won female comedy performance for Derry Girls, and Sex Education actor Ncuti Gatwa won best male comedy performance.
In the drama categories, performance awards went to Stephen Graham for The Virtues and Tamara Lawrance for The Long Song.
Jane Featherstone, the former Kudos chief and now founder of Sister Pictures, was presented with the Judges’ Award.
Comedian Paul Merton hosted the live-broadcaster ceremony, which was made available via the RTS website.
The RTS awards recognize UK and international co-productions that were made between November 2018 and October 2019.
“We are all facing an incredibly difficult time and rightfully have made responsible changes to the format of the RTS Programme Awards. Despite this, we would like to acknowledge the incredible contribution of all our nominees to the UK’s television output and celebrate our deserving winners,” said outgoing RTS Programme Awards chair Wayne Garvie. “This is my last year in the role of Chair of the RTS Programme Awards and throughout my tenure I have been proud to witness the outstanding talent in the UK, and have been repeatedly inspired by the creativity across our industry.”