In 1891 he may be the Charles OCannor aged 11 and born in Dublin, Ireland and at a possibly RC coeducational establishment at North Street, Rotherfield.
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In 1901 there was a Charles O’Connor, actor, aged 23 boarding in Fenny Stratford, Newport Pagnel and born in Ireland.
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This is probably him and his wife in 1911, though I am surprised that he was working as a chauffeur:

Reference: RG14 - PN344 RD SD ED- SN81
Address: 26b Buer Road, Fulham S W
Registration District: Fulham
Sub District: South Fulham
Civil Parish: Fulham

Surname Forename Age Gender Relation Marriage Status  Years Married Occupation Birth Place

O'connor Charles 31 Male Head Married  4  Chauffeur (Domestic) Blackrock, Dublin
O'connor Esther 32 Female Wife  Married  4  None  Not Known, -
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On the basis that the 1911 census is right that they had no children up to that date, these are the births of O’Connors with mother’s maiden name of Beaumont from 1911 to 1940:

Surname   First name(s)   Mother   District  Vol  Page

Births Sep 1912   (>99%)
O'Connor Dennis Beaumont London C. 1c   11
Births Jun 1917   (>99%)
O'Connor Laurence C Beaumont Holborn 1b  869
Births Sep 1919   (>99%)
O'Connor Rosina A Beaumont Holborn 1b  910
Births Mar 1921   (>99%)
O'Connor Ellen M Beaumont Holborn 1b 1074
Births Dec 1922   (>99%)
O'Connor William D Beaumont Holborn 1b  958
Births Sep 1926   (>99%)
O'CONNOR Dennis B Beaumont Holborn 1b  846
Births Dec 1929   (>99%)
O'Connor John H Beaumont London C. 1c    5

The obvious reason why there were two Dennis births is that the firs one died.  There are in fact three infant deaths aged 0 from 1915 to 1926 in the London area, but none look like the first Dennis.
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Their marriage:

Name Charles Joseph W O'connor
District Marylebone, London
Spouse Esther Beaumont [Select]
Florence May Lawrence [Select]
Why is there more than one spouse?
[More Spouse Matches]
Page 1240
Volume 1A
Registered October - December 1906

Oct 2012, TFPL: I have followed Brenda Graham in electing Esther Beaumont as his wife, but as yet I have no evidence to corroborate this.  They are not in the 1911 census (on The Genealogist).

FreeBMD shows these marriages:

Surname   First name(s)   District   Vol  Page
Marriages Dec 1906   (>99%)
BEAUMONT Esther Marylebone 1a 1240
Lawrence Florence May    Marylebone 1a 1240
O'CONNOR Charles Joseph W Marylebone 1a 1240
STOREY Richard James    Marylebone 1a 1240

So it might be worth looking for the other couple in the 1911 census…  But nothing came of that, though a Charles and Florence O’Connor were found in Swindon in 1911 with a marriage four years previously.

There are seven children born to an O’Connor father and Beaumont mother between 1910 and 1940, all in London, and 15 or so to O’Connor and Lawrence in the same period, but all over Britain.  This tends to confirm the O’Connor to Beaumont marriage but to make sure of it, I have ordered a certificate.

18 Oct 2012, TFPL: The cert has arrived and has:

1906. Marriage solemnised at St James Church, Spanish Place, St Marylebone dist, County of London.

Cert NO: 155
Date: 2 oct 1906
Name  Age  Condition  Profession  Residence  Father  Pa’ occ.

Charles 27 Bachelor Motor engr 1 Portman Valentine  Ind
Joseph Mews South, O’Connor   Means
Wilfred St Marylebons
O’Connor

Esther 27 Spinster --- 23 Little ---   ---
Beaumont Russell St
Bloomsbury

Witnesses:  Kate Cook, Valentine O’Connor

Celebrant:  William N Roche
Deputy Registrar: Hugh Stokes
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