Just before the Labour Party's deadline for nominations to the panel of Welsh Assembly candidates closed at midday yesterday, he handed in his application at the party's Welsh headquarters in Cardiff.
More than 400 names are now on the list, and the process of fining the number down is expecting to take several weeks or even months.
The 60-strong body will be elected in May next year - 40, one for each of the Welsh Westminster seats by the first-past -the-post system, and 20 by proportional representation drawing on party lists.
Mr Davies who represents the safe Labour seat of Caerphilly told a news conference at Transport House in Cardiff: "We must await developments but I am delighted to put my name forward."
He said he had consulted Tony Blair, the Prime Minister, discussed the matter with his constituency party and talked it over with his wife Christina.
At 51, Mr Davies is nearly 10 years younger than Donald Dewar, the Secretary of State for Scotland, who has already indicated that he will leave the Commons and seek election to the Scottish parliament.
Mr Davies, who has long experience in the party, first in Welsh local government and then as shadow Welsh secretary, is counted a Cabinet success. He lived down a reputation while in opposition as having republican tendencies.
He is credited with successfully steering the devolution debate to a favourable, albeit narrow outcome. That was largely achieved by Mr Davies' ability to bring on board the Liberal Democrats and Plaid Cymru - a troika that delivered a "yes" vote.
It is understood that Mr Davies will carry on as Secretary of State, and should he go for the Assembly option - almost a forgone conclusion - he intends to continue as a Cabinet minister for "a short transitional period".
"I shall be leading Labour's Assembly election campaign," he declared.
Two other leading Labour figures are understood to be keen to hold a significant position in the Welsh Assembly. Rhodri Morgan MP for Cardiff West and Wayne David MEP for South Wales Central and leader of Labour's Euro MPs are both contenders.
With the odds heavily on the Secretary of State taking the "Prime Minister of Wales" mantle, speculation over a successor Secretary of State is beginning to surface. One favoured replacement is understood to be Paul Murphy, MP for Torfaen, who as a Northern Ireland minister has won praise from Mo Mowlam for his contribution to the peace talks.Reuse content