Un-Nooh overcame Liam Highfield in qualifying, and his reward is a second meeting with five-time world champion O'Sullivan, six years after he won their encounter at the German Masters.
The 44-year-old O'Sullivan has given his reaction to facing Un-Nooh in the opening round, and he is certainly not feeling an edge around the match given the good nature of his opponent.
'It is about balancing and doing what works for you' - Robertson
"He’s a guy I like playing and one of the few I don’t actually mind losing to as he’s such a nice guy," O'Sullivan told Eurosport after the draw.
Everyone on the circuit would love to see him do well and win tournaments as he’s a very humble and respected by everyone.
Meanwhile, world number one Judd Trump will begin his title defence against Ford, who edged out Stuart Carrington 10-8 in the final round of qualifying.
The tournament starts on Friday and runs until August 16, with all 17 days live on Eurosport and Eurosport Player.
'No chance!' - O'Sullivan on controversial missed 147
World Snooker Championship first round draw
- Judd Trump (1) v Tom Ford
- Yan Bingtao (16) v Elliot Slessor
- Stephen Maguire (9) v Martin Gould
- Kyren Wilson (8) v Anthony Hamilton
- John Higgins (5) v Matthew Stevens
- David Gilbert (12) v Kurt Maflin
- Jack Lisowski (13) v Anthony McGill
- Mark Allen (4) v Jamie Clarke
- Mark Williams (3) v Alan McManus
- Stuart Bingham (14) v Ashley Carty
- Ding Junhui (11) v Mark King
- Ronnie O’Sullivan (6) v Thepchaiya Un-Nooh
- Mark Selby (7) v Jordan Brown
- Shaun Murphy (10) v Noppon Saengkham
- Barry Hawkins (15) v Alexander Ursenbacher
- Neil Robertson (2) v Liang Wenbo
Jimmy White vs Judd Trump's Eurosport Masters shot of the championship pot
'It is a tough sport, mentally it is tough' - O'Sullivan says Selby has a choice to make