According to the help file from the Canadian government for filling out the ETA it says the following on the application: Given name(s) / first
name(s) Please enter exactly as shown on your passport or identity document Source: https://www.canada.ca/content/dam/ircc/migration/ircc/english/pdf/eta/english.pdf
(Page 11)
So you should put it in,
exactly like it says on the passport.
If you're not sure what you should put in (not just two name forms, non-latin script) and your passport has a machine readable zone, you should probably use the names in the same grouping as done there.
The format are two lines at the bottom of the identity page of your passport where the first line is of the following format:
P[4 unimportant letters][family name with blanks and other non-latin characters replaced by <]<<
[given names also separated by <] ( [] being used by me to separate the fields).
Note that the ETA help pdf has some more detailed explanations that are worth reading for everyone with unusual name(s).
travel.stackexchange.com/users/16564/Voo
" my First name only into the Given Name(s) field " If it asked for "first name" a single name might be acceptable.
But it didn't.
Notice
the "(s)".
That means that there can be more than one name.
Notice
the "Given", that means all but your family name, which was inherited not given.
The form didn't ask for "First name"; it asked for "Given name(s)".
Many countries are improving their forms by saying "Given" rather than "First", since there are many societies where the first name is actually the family name.(e.g.
in Chinese, "Xi Jinping", "Xi Jin Ping", and "Xi Jin-Ping" are all valid Romanizations of "习近平".
"
Xi" is first, but it is the family name.)
EDIT:
@Voo says that the form contains this instruction: Please enter exactly as shown on your passport or travel document.
That should remove any confusion.
Whatever names are on the passport you are going to be using should be the names you use on the form.
No more, no less.
travel.stackexchange.com/users/97834/Ray Butterworth
My name is (based on catholic), using the same form as David's answer: A:
given (first) name B: middle name 1 (or second first name)
C: middle name 2 (or third first name)
D: middle name 3 (or fourth first name)
E: family/surname
To make things even more complicated, my nickname is different than A; it is not in any official paper.
So, on my passport I have to use A until D, and not my nickname.
travel.stackexchange.com/users/3582/Michel Keijzers
If your first and two middle names are printed under ‘Given names’ in your passport, and you are asked to provide ‘Given name(s)’ not ‘First name’, you should include all three.
Example
: I just applied for an ESTA.
I have a first and middle name (I’m known by my middle, not first, name), and my passport shows both names under ‘Given names’ and in the machine readable data section.
When I uploaded this section during the application process, the system captured both names in the ‘Given names’ section of the application.
Other examples: https://www.canadavisa.com/canada-immigration-discussion-board/threads/is-middle-name-part-of-given-name.202730/
travel.stackexchange.com/users/60926/Traveller
Your title question is answered by your question itself: you consider your middle names as middle names, and not as your first name.
Thus, I would complete applications so as to track your passport names as closely as possible.
In my culture, it'd go like this: A =
given (first) name B =
middle name #1
C = middle name
#2 D = family/surname Like this: If the application has only two fields, enter A and D in the appropriate fields.
If the application has three fields, enter A in the first field, B and C (with an intervening space if possible) in the second field, and D in the third space.
Different cultures may attribute names differently.
travel.stackexchange.com/users/76708/DavidSupportsMonica
My full name is four names long - First name, Middle name, Middle name, Last name.  Whenever asked for my  Given Name  I have always supplied my First name (not either of my middle names).  This week I have applied for a Canadian eTA, and put (as per usual) my First name only into the  Given Name(s)  field.  But now I'm wondering, should I have included my middle names also into that form?  In my passport I have all four names printed.
Is a Middle Name a Given Name?
travel.stackexchange.com
<canada><paperwork><eta>
travel.stackexchange.com/questions/147267
travel.stackexchange.com/users/40422/Midavalo
Whatever names are on the passport you are going to be using should be the names you use on the form.  If your first and two middle names are printed under ‘Given names’ in your passport, and you are asked to provide ‘Given name(s)’ not ‘First name’, you should include all three. Your name should be entered as it appears in your passport.
Your name should be entered as it appears in your passport.