In Shakespeare's sonnets, the theme of human love in its many forms is central. Scholars have pointed out the diverse types of love depicted in these poems, including spiritual, erotic, parental, and filial love. They observe that these works delve into the contradictory aspects of human passion from various perspectives, sometimes idealizing love and other times treating it with irony. Many critics emphasize Shakespeare's innovative approach to the traditions of courtly and Petrarchan love. They contrast the Renaissance ideal of human love, which harmonizes earthly and heavenly desires, with the sonnets' depiction of these desires as opposing extremes.

Some critics propose that in Shakespeare's sonnets, love is at times depicted as a source of inspiration for creating transcendent art, with the lover claiming he can immortalize his beloved's beauty and worth through poetry. In this manner, love and art unite to conquer time and its destructive powers. Love is also portrayed as a force that can lead a person to attain the highest virtues of human nature, such as patience, understanding, selflessness, and forgiveness. However, some commentators suggest that the sonnets' portrayal of self-sacrificing love serves as a satire of the servile lover in the sonnet tradition, who readily assumed the role of an obedient servant, meeting his mistress's every need. Critics have also noted that love in the sonnets can manifest as infatuation, clouding the lover's judgment. Particularly in Sonnets 127-152, love is depicted as lust or carnal desire, a passion that corrupts the soul and diminishes the lover. Yet, some critics observe that the Dark Lady sonnets humorously and vibrantly portray sensual love as an essential aspect of human nature. Additionally, love is shown as friendship, with some commentators interpreting the bond between the Poet and the Friend as reflecting the classical notion that a profound friendship between two men holds greater intrinsic value than a sexual relationship between a man and a woman.

Over the centuries, scholars have variously denied, confronted, accepted, and celebrated the ambiguous eroticism present in the sonnets. A seventeenth-century editor even changed all masculine pronouns and adjectives to feminine ones, turning the beloved of Sonnets 1-126 into a woman. Editors and commentators of the eighteenth and nineteenth centuries struggled with the implications of masculine address in the core part of the sequence. Twentieth-century critics remain divided on whether the relationship between the Poet and the Friend is sexual. Nevertheless, nearly all agree that regardless of the nature of their relationship, it does not provide insight into the personal life of the sonnets' author. Stephen Booth's statement on the biographical fallacy is frequently cited: "William Shakespeare was almost certainly homosexual, bisexual, or heterosexual. The sonnets provide no evidence on the matter."

In Shakespeare's sonnets, one of the main themes surrounding love is the betrayal associated with it. Most experts concur that while the Poet accuses the Dark Lady of being sexually unfaithful, he is significantly more disturbed by the Friend's betrayal. Critics have noted that the Poet fears the young man might be unreliable, yet he tries to suppress these concerns and place his trust in him. When the Friend betrays this trust, the Poet initially tries to justify and pardon the infidelity but eventually rebukes the young man for his deceit and himself for having trusted him. Many scholars point out that the betrayal's impact is intensified because the Poet believes there is a direct link between the young man's external beauty and his character. Upon discovering a disparity instead of a harmony, the Poet is heartbroken. Nevertheless, most commentators agree that the Poet's affection for the young man persists, albeit tempered by...