There are sonnets in several of Shakespeare's plays, especially, though not exclusively, in his earlier ones.
Best know among these may be the one that Romeo and Juliet share in Act 1, scene 5:
[To JULIET] If I profane with my unworthiest hand
This holy shrine, the gentle fine is this:
My lips, two blushing pilgrims, ready stand
To smooth that rough touch with a tender kiss.
Good pilgrim, you do wrong your hand too much,
Which mannerly devotion shows in this;
For saints have hands that pilgrims' hands do touch,
And palm to palm is holy palmers' kiss.
Have not saints lips, and holy palmers too?
Ay, pilgrim, lips that they must use in prayer.
O, then, dear saint, let lips do what hands do;
They pray, grant thou, lest faith turn to despair.
Saints do not move, though grant for prayers' sake.
Then move not, while my prayer's effect I take.
And they immediately begin another sonnet but they are interrupted by Juliet's nurse.
Another sonnet can be found in the Prologue to Act 2:
Now old desire doth in his death-bed lie,
And young affection gapes to be his heir;
That fair for which love groan'd for and would die,
With tender Juliet match'd, is now not fair.
Now Romeo is beloved and loves again,
Alike betwitched by the charm of looks,
But to his foe supposed he must complain,
And she steal love's sweet bait from fearful hooks:
Being held a foe, he may not have access
To breathe such vows as lovers use to swear;
And she as much in love, her means much less
To meet her new-beloved any where:
But passion lends them power, time means, to meet
Tempering extremities with extreme sweet.
Love's Labour's Lost contains several sonnets, for example the one read by Nathanael in Act 4, scene 2:
If love make me forsworn, how shall I swear to love?
Ah, never faith could hold, if not to beauty vowed!
Though to myself forsworn, to thee I’ll faithful prove;
Those thoughts to me were oaks, to thee like osiers bowed.
Study his bias leaves and makes his book thine eyes,
Where all those pleasures live that art would comprehend.
If knowledge be the mark, to know thee shall suffice.
Well learned is that tongue that well can thee commend,
All ignorant that soul that sees thee without wonder;
Which is to me some praise, that I thy parts admire.
Thy eye Jove’s lightning bears, thy voice his dreadful thunder,
Which, not to anger bent, is music and sweet fire.
Celestial as thou art, O, Pardon love this wrong,
That sings heaven’s praise with such an earthly tongue.
This "sonnet" is unusual in that it consists of hexameters instead of pentameters.
In Act 4, scene 3 Longaville reads a sonnet:
Did not the heavenly rhetoric of thine eye,
'Gainst whom the world cannot hold argument,
Persuade my heart to this false perjury?
Vows for thee broke deserve not punishment.
A woman I forswore; but I will prove,
Thou being a goddess, I forswore not thee:
My vow was earthly, thou a heavenly love;
Thy grace being gain'd cures all disgrace in me.
Vows are but breath, and breath a vapour is:
Then thou, fair sun, which on my earth dost shine,
Exhalest this vapour-vow; in thee it is:
If broken then, it is no fault of mine:
If by me broke, what fool is not so wise
To lose an oath to win a paradise?
Dumain's poem from the same scene is also "sonnet" that uses seven-syllable lines instead of pentameters:
On a day--alack the day!--
Love, whose month is ever May,
Spied a blossom passing fair
Playing in the wanton air:
Through the velvet leaves the wind,
All unseen, can passage find;
That the lover, sick to death,
Wish himself the heaven's breath.
Air, quoth he, thy cheeks may blow;
Air, would I might triumph so!
But, alack, my hand is sworn
Ne'er to pluck thee from thy thorn;
Vow, alack, for youth unmeet,
Youth so apt to pluck a sweet!
The three "sonnets" from Act 4, scene 3 were pirated by the unscrupulous printer William Jaggard, who included them in an anthology entitled The Passionate Pilgrim, which he attributed in its entirety to Shakespeare, even though not all poems in the volume were actually by Shakespeare.
The Chorus at the end of Henry V also uses the sonnet form:
Thus far, with rough and all-unable pen,
Our bending author hath pursued the story,
In little room confining mighty men,
Mangling by starts the full course of their glory.
Small time, but in that small most greatly lived
This star of England: Fortune made his sword;
By which the world's best garden be achieved,
And of it left his son imperial lord.
Henry the Sixth, in infant bands crown'd King
Of France and England, did this king succeed;
Whose state so many had the managing,
That they lost France and made his England bleed:
Which oft our stage hath shown; and, for their sake,
In your fair minds let this acceptance take.
Helen's letter to the countess in Act 3, scene 4 of All's Well That Ends Well is also a sonnet:
I am Saint Jaques' pilgrim, thither gone:
Ambitious love hath so in me offended,
That barefoot plod I the cold ground upon,
With sainted vow my faults to have amended.
Write, write, that from the bloody course of war
My dearest master, your dear son, may hie:
Bless him at home in peace, whilst I from far
His name with zealous fervor sanctify:
His taken labours bid him me forgive;
I, his despiteful Juno, sent him forth
From courtly friends, with camping foes to live,
Where death and danger dogs the heels of worth:
He is too good and fair for death and me:
Whom I myself embrace, to set him free.