The Very Reverend Sandy McDonald, a former Moderator of the General Assembly of the Church of Scotland, disclosed that he was suffering from lung condition pulmonary fibrosis and was now living in a retirement flat.
He has made an end-of life plan and has called on senior church figures to back proposed laws to give terminally-ill people “assistance towards a peaceful death”.
Earlier this month, ex-Dr Who actor Tennant dedicated his special recognition prize at the National Television Awards to his 77-year-old father.
Rev McDonald, of Paisley, Renfrewshire, said he did not know how long he had left to live but said it was time to give dying people more rights over end-of-life care.
He said: “I have pulmonary fibrosis. It just gets worse, there is no cure. I have had to address it and decide what to do.
“I have an advance directive which says ‘do not resuscitate’. I do not want to be fed by something in my stomach.
“What I do want is the right to a peaceful end to my life.”
He added: “I think we have the wrong slant, the wrong emphasis.
“The phrase - assisted suicide - has criminal overtones in the minds of many people.
“We need to take seriously the provision of a peaceful end of life for all those who need and want it.
“Of course there would have to be safeguards and that should be discussed.”
The Church of Scotland is formally against a change in the law such as the Assisted Suicide Bill, which is currently being debated at Holyrood.
The Bill, originally introduced by the late Margo MacDonald, has the aim of legalising suicide for terminally-ill people through the Scottish Parliament.
Rev McDonald said many terminally ill people wanted to die and insisted current legislation was putting a strain on the NHS. He called on the Kirk to discuss the issue at this year’s assembly in May.
He said: “We have got so many people in our nursing homes, in our care homes and our bed-blocked hospitals, whether elderly or seriously ill, who are saying ‘it’s time for me to die’.
“I sympathise hugely with them.
“The doctors and nurses have their hands tied because they are liable to end up in court.
“I believe it is only just that the Church come together and discuss this.”
Rev McDonald filmed a special tribute to his actor son which was played before he collected his award at the NTAs.
In his acceptance speech Tennant, 43, said: “I would like to dedicate this to my dad. He is an inspiration and a role model, so thanks Sandy.”
The star’s father, whose wife Helen died in 2007, said he was delighted at the tribute.
He added: “The event brought a great deal of joy.
“Friends from all over have been ringing since the broadcast. Some people I have not heard from for years have been in touch to say how delighted they were. It was good to talk to them.”
Rev McDonald was a minister in Lanarkshire, West Lothian and Paisley before becoming the General Secretary of the Church of Scotland’s Board of Ministry. He retired in 2002.