There were a few differences in the lyrics of other versions of this song, so
I changed them so they hold true to the original Dubliners version and I
placed the chords in correspondence to where they change in the song. You
need to play it by ear but overall it should be fairly easy to pick up.
Standard tuning, adh m?r!

          G                                 
In a neat little town they call Belfast,
C             A7          D7
apprentice to trade I was bound
   G                   Em
An Many an hours sweet happiness,
       C             D           G
have I spent in that neat little town
                               C            A7                   D7
A sad misfortune came over me, which caused me to stray from the land
    G                        Em         C               D            G
Far away from me friends and relations, betrayed by the black velvet band


Chorus:

G                                   
Her eyes they shone like diamonds
C                              D7
I thought her the queen of the land
        G                     Em
And her hair it hung over her shoulder
     C         D            G
Tied up with a black velvet band


G                             
I took a stroll down Broadway,
C       A7              D7
meaning not long for to stay
G                               Em
When who should I meet but this pretty fair maid
C                D         G
come a-traipsing along the highway
G                               C               A7          D7
She was both fair and handsome, her neck it was just like a swan
G                             Em        C              D            G
And her hair it hung over her shoulder, tied up with a black velvet band

-Chorus-

G
I took a stroll with this pretty fair maid, 
C               A7         D7
and a gentleman passing us by
G                                  Em
Well I knew she meant the doing of him, 
C                  D             G
by the look in her roguish black eye
G                                         C               A7       D7
A goldwatch she took from his pocket, and placed it right in to my hand
G                                    Em   C                D            G
And the very first thing that I said was, bad ?cess to the black velvet band

-Chorus-

G
Before the judge and the jury,
C              A7     D7
next morning I had to appear
G                          Em
The judge, he says to me: "Young man,
C         D            G
your case it is proven clear
G                                                 C         A7            D7
We'll give you seven years penal servitude, to be spent far away from the land
G                              Em         C               D            G
Far away from your friends and relations, betrayed by the black velvet band"

-Chorus-

G
So come all you jolly young fellows
C         A7      D7
a warning take by me
G                               Em
When you are out on the town me lad,
C             D      G
beware of the pretty colleens
G                                             C           A7        D7
they?ll feed you with strong drink, Me lads, 'til you are unable to stand
G                                         Em         C         D           G
And the very first thing that you'll know is, you've landed in Van Diemens Land

Outro Chorus:

G
Her eyes they shone like diamonds
C                            D7
Her neck, it was just like a swan
        G                     Em
And her hair it hung over her shoulder
     C         D            G
Tied up with a black velvet band