Theodore "Laurie" Laurence, orphaned grandson of wealthy neighbor Mr. James Laurence, resides with his stern grandfather in the adjacent estate. Initially lonely and isolated within his privileged upbringing, he forms a close bond with the March sisters, particularly Jo March. Their friendship thrives on shared literary interests, a love of adventure, mutual disdain for societal constraints, intellectual exchanges, creative pursuits, and playful teasing. Laurie's mischievous personality contrasts with his grandfather's demeanor, though he deeply respects his guardian. Finding warmth and acceptance in the March household, he becomes a frequent visitor.

Laurie's feelings for Jo deepen into romantic attraction, leading to a marriage proposal. After Jo declines, he travels to Europe with his grandfather, seeking emotional distance. Abroad, he experiences personal growth and refines his social graces. He reconnects with Amy March, the youngest March sister, also traveling in Europe under Aunt March's patronage. Their shared experiences foster mutual understanding and a romantic relationship, culminating in marriage.

Later, married to Amy, Laurie becomes a supportive husband and benefactor. He provides financial assistance to the March family and supports Jo's educational endeavors, notably contributing to the establishment and operation of Plumfield, the school she founds with her husband, Professor Bhaer. Laurie interacts with Plumfield's students, sharing anecdotes of his youth and connection to the March family, becoming a respected, avuncular figure within the extended Plumfield community.