In 1805, Smirke became a member of the Society of Antiquaries of London and the Architects' Club.
His first official appointment came in 1807 when he was made architect to the Royal Mint.
He was elected an Associate of the Royal Academy on 7 November 1808, and a full Academician on 11 February 1811, his diploma work consisting of a drawing of a reconstruction of the Acropolis of Athens.
He only ever exhibited five works at the Academy, the last in 1810.

Smirke's relations with Soane reached a new low after the latter, who had been appointed Professor of Architecture at the Royal Academy, heavily criticised Smirke's design for the Covent Garden Opera House in his fourth lecture on 29 January 1810.
He said:
 
The practise of sacrificing everything to one front of a building is to be seen, not only in small houses where economy might in some degree apologize for the absurdity, but it is also apparent in large works of great expense ..... And these drawings of a more recent work (here two drawings of Covent Garden theatre were displayed) point out the glaring impropriety of this defect in a manner if possible still more forcible and more subversive of true taste.
The public attention, from the largeness of the building, being particularly called to the contemplation of this national edifice
Together with John Nash and Sir John Soane, he became an official architect to the Office of Works in 1813 (an appointment he held until 1832) at a salary of £500 per annum, thereby reaching the height of the profession.
In 1819 he was made surveyor of the Inner Temple.
In 1819, he married Laura Freston, daughter of The Reverend Anthony Freston, the great-nephew of the architect Matthew Brettingham.
The only child of the marriage was a daughter Laura.
In 1820, he was made surveyor of the Duchy of Lancaster, and also in 1820 he became treasurer to the Royal Academy.
He was knighted in 1832, and received the RIBA Royal Gold Medal for Architecture in 1853.
Smirke lived at 81 Charlotte Street, London.
There is a blue plaque commemorating his residence on the outside of the building.
He retired from practise in 1845, after which Robert Peel made him a member of the Commission for London Improvements.
In 1859, he resigned from the Royal Academy and retired to Cheltenham, where he lived in Montpellier House, Suffolk Square.
He died there on 18 April 1867 and was buried in the churchyard of St Peter's in Leckhampton.
His estate was worth £90,000.

He is known to have designed or remodelled over twenty churches, more than fifty public buildings and more than sixty private houses.
This productivity inspired James Planché's 1846 chorus in his burlesque of Aristophanes' The Birds:	
	
Go to work, rival Smirke
	
Make a dash, À la Nash
	
Something try at, worthy Wyatt
	
Plans out carry, great as Barry
	
The rapid rise of Smirke was due to political patronage.
He was a Tory at a time when this party was in the ascendant.
His friends at the Royal Academy such as Sir Thomas Lawrence, George Dance, Benjamin West and Joseph Farington were able to introduce him to patrons such as: John Hamilton, 1st Marquess of Abercorn; Henry Dundas, 1st Viscount Melville; Sir George Beaumont, 7th Baronet; George Hamilton-Gordon, 4th Earl of Aberdeen; Francis Seymour-Conway, 3rd Marquess of Hertford; Henry Bathurst, 3rd Earl Bathurst; John 'Mad Jack' Fuller and William Lowther, 2nd Earl of Lonsdale.
These politicians and aristocrats ensured his rapid advancement and several were to commission buildings from Smirke themselves.
Thomas Leverton Donaldson described Smirke as able to please "Men whom it was proverbially impossible to please".
His patron at Lowther Castle William Lowther, 1st Earl of Lonsdale said he was "ingenious, modest and gentlemanly in his manners".
In 1805, Smirke became a member of the Society of Antiquaries of London and the Architects' Club. His first official appointment came in 1807 when he was made architect to the Royal Mint. He was elected an Associate of the Royal Academy on 7 November 1808, and a full Academician on 11 February 1811, his diploma work consisting of a drawing of a reconstruction of the Acropolis of Athens. He only ever exhibited five works at the Academy, the last in 1810.
Smirke's relations with Soane reached a new low after the latter, who had been appointed Professor of Architecture at the Royal Academy, heavily criticised Smirke's design for the Covent Garden Opera House in his fourth lecture on 29 January 1810. He said:
 
The practise of sacrificing everything to one front of a building is to be seen, not only in small houses where economy might in some degree apologize for the absurdity, but it is also apparent in large works of great expense ..... And these drawings of a more recent work (here two drawings of Covent Garden theatre were displayed) point out the glaring impropriety of this defect in a manner if possible still more forcible and more subversive of true taste. The public attention, from the largeness of the building, being particularly called to the contemplation of this national edifice
Together with John Nash and Sir John Soane, he became an official architect to the Office of Works in 1813 (an appointment he held until 1832) at a salary of £500 per annum, thereby reaching the height of the profession. In 1819 he was made surveyor of the Inner Temple. In 1819, he married Laura Freston, daughter of The Reverend Anthony Freston, the great-nephew of the architect Matthew Brettingham. The only child of the marriage was a daughter Laura. In 1820, he was made surveyor of the Duchy of Lancaster, and also in 1820 he became treasurer to the Royal Academy. He was knighted in 1832, and received the RIBA Royal Gold Medal for Architecture in 1853. Smirke lived at 81 Charlotte Street, London. There is a blue plaque commemorating his residence on the outside of the building. He retired from practise in 1845, after which Robert Peel made him a member of the Commission for London Improvements. In 1859, he resigned from the Royal Academy and retired to Cheltenham, where he lived in Montpellier House, Suffolk Square. He died there on 18 April 1867 and was buried in the churchyard of St Peter's in Leckhampton. His estate was worth £90,000.
He is known to have designed or remodelled over twenty churches, more than fifty public buildings and more than sixty private houses. This productivity inspired James Planché's 1846 chorus in his burlesque of Aristophanes' The Birds:	
	
Go to work, rival Smirke
	
Make a dash, À la Nash
	
Something try at, worthy Wyatt
	
Plans out carry, great as Barry
	
The rapid rise of Smirke was due to political patronage. He was a Tory at a time when this party was in the ascendant. His friends at the Royal Academy such as Sir Thomas Lawrence, George Dance, Benjamin West and Joseph Farington were able to introduce him to patrons such as: John Hamilton, 1st Marquess of Abercorn; Henry Dundas, 1st Viscount Melville; Sir George Beaumont, 7th Baronet; George Hamilton-Gordon, 4th Earl of Aberdeen; Francis Seymour-Conway, 3rd Marquess of Hertford; Henry Bathurst, 3rd Earl Bathurst; John 'Mad Jack' Fuller and William Lowther, 2nd Earl of Lonsdale. These politicians and aristocrats ensured his rapid advancement and several were to commission buildings from Smirke themselves. Thomas Leverton Donaldson described Smirke as able to please "Men whom it was proverbially impossible to please". His patron at Lowther Castle William Lowther, 1st Earl of Lonsdale said he was "ingenious, modest and gentlemanly in his manners".
Robert Smirke (architect)