Lang received the jury verdict in just under 2 hours after a short 11-day trial for the horrifying murder which occurred in October 2015.
It is believed the Brisbane socialite was viciously stabbed to death with a cooking knife and impaled to the bed by Lang after she refused to leave her husband of 40 years.
Her body was found at her Kangaroo Point home with the knife's handle inside her body.
Lang although claimed he went to sleep around 11pm and found her dead when he awoke in the morning.
He then went on to say that Maureen was diagnosed with bipolar and had gone into a panic before committing suicide.
In a police interview, Lang told a Detective: 'Did I kill Maureen? No, I didn't stab her.'
'Violence scares me. I hate violence. I loved her with all my heart' he said.
Post-mortem reports although showed that the former model could not have killed herself and ruled the most likely cause of death was murder.
Thomas Lang will now serve at least 20 years before being allowed parole.