Speaking outside Stormont Castle, Mr Paisley admitted the last 10 months had not been without controversy.
Most recently he came under fire over receiving three pay-checks from taxpayers as a junior minister and a Westminster aid to his MP father and Assembly First Minister.
Doubts and speculation abounded in December last year when an SDLP MLA asked the Assembly's Standards and Privileges Committee to investigate the role of the DUP's Ian Paisley Jnr in a £50m land deal involving Seymour Sweeney.
-- Advertisement --
Although the Ombudsman's investigation could not find evidence to incriminate Mr Paisley jnr, the minister has been unable to shirk continued pressure by opposition parties.
Ian Paisley jnr said: "Personal criticism, unfounded allegations, innuendo and attacks on me personally, followed by Ombudsman's reports that have cleared me - this relentless period of criticism by those who have decided on this path has been unceasing.
"The criticism has been a distraction and has got in the way of the activities of this government, and importantly it has gotten in the way of the activities of my political party."
The junior minister's resignation will come into affect when a replacement is found estimated to be within the next few days.
The decision is a further blow for his party, the DUP, especially after losing last week's Banbridge by-election to the Ulster Unionsists.
(BMcC)
