Lowell married the novelist and short-story writer Jean Stafford in 1940.
Before their marriage, in 1938, Lowell and Stafford were in a serious car crash, in which Lowell was at the wheel, that left Stafford permanently scarred, while Lowell walked away unscathed.
The impact crushed Stafford's nose and cheekbone and required her to undergo multiple reconstructive surgeries.
The couple had a tumultuous marriage—the poet Anthony Hecht characterized it as "a tormented and tormenting one"— that ended in 1948.
Shortly thereafter, in 1949, Lowell married the writer Elizabeth Hardwick with whom he had a daughter, Harriet, in 1957.
After Hardwick's death in 2007, The New York Times would characterize the marriage as "restless and emotionally harrowing," reflecting the very public portrait of their marriage and divorce as Lowell captured it in his books For Lizzie and Harriet and The Dolphin.
After 23 years of marriage to Elizabeth Hardwick, in 1970, Lowell left her for Caroline Blackwood.
Blackwood and Lowell were married in 1972 in England where they decided to settle and where they raised their son, Sheridan.
Lowell also became the stepfather to Blackwood's young daughter, Ivana, for whom he would write the sonnet "Ivana," published in his book The Dolphin.

Lowell had a close friendship with the poet Elizabeth Bishop that lasted from 1947 until Lowell's death in 1977.
Both writers relied upon one another for critiques of their poetry (which is in evidence in their voluminous correspondence, published in the book Words in Air: the Complete Correspondence between Elizabeth Bishop and Robert Lowell in 2008) and thereby influenced one another's work.
Bishop's influence over Lowell can be seen at work in at least two of Lowell's poems: "The Scream" (inspired by Bishop's short story "In the Village") and "Skunk Hour" (inspired by Bishop's poem "The Armadillo"), and the scholar Thomas Travisano notes, more broadly, that "Lowell's Life Studies and For the Union Dead, his most enduringly popular books, were written under Bishop's direct influence."

Lowell also maintained a close friendship with Randall Jarrell from their 1937 meeting at Kenyon College until Jarrell's 1965 death.
Lowell openly acknowledged Jarrell's influence over his writing and frequently sought out Jarrell's input regarding his poems before he published them.
In a letter to Jarrell from 1957, Lowell wrote, "I suppose we shouldn't swap too many compliments, but I am heavily in your debt."
Lowell married the novelist and short-story writer Jean Stafford in 1940. Before their marriage, in 1938, Lowell and Stafford were in a serious car crash, in which Lowell was at the wheel, that left Stafford permanently scarred, while Lowell walked away unscathed. The impact crushed Stafford's nose and cheekbone and required her to undergo multiple reconstructive surgeries. The couple had a tumultuous marriage—the poet Anthony Hecht characterized it as "a tormented and tormenting one"— that ended in 1948. Shortly thereafter, in 1949, Lowell married the writer Elizabeth Hardwick with whom he had a daughter, Harriet, in 1957. After Hardwick's death in 2007, The New York Times would characterize the marriage as "restless and emotionally harrowing," reflecting the very public portrait of their marriage and divorce as Lowell captured it in his books For Lizzie and Harriet and The Dolphin. After 23 years of marriage to Elizabeth Hardwick, in 1970, Lowell left her for Caroline Blackwood. Blackwood and Lowell were married in 1972 in England where they decided to settle and where they raised their son, Sheridan. Lowell also became the stepfather to Blackwood's young daughter, Ivana, for whom he would write the sonnet "Ivana," published in his book The Dolphin.
Lowell had a close friendship with the poet Elizabeth Bishop that lasted from 1947 until Lowell's death in 1977. Both writers relied upon one another for critiques of their poetry (which is in evidence in their voluminous correspondence, published in the book Words in Air: the Complete Correspondence between Elizabeth Bishop and Robert Lowell in 2008) and thereby influenced one another's work. Bishop's influence over Lowell can be seen at work in at least two of Lowell's poems: "The Scream" (inspired by Bishop's short story "In the Village") and "Skunk Hour" (inspired by Bishop's poem "The Armadillo"), and the scholar Thomas Travisano notes, more broadly, that "Lowell's Life Studies and For the Union Dead, his most enduringly popular books, were written under Bishop's direct influence."
Lowell also maintained a close friendship with Randall Jarrell from their 1937 meeting at Kenyon College until Jarrell's 1965 death. Lowell openly acknowledged Jarrell's influence over his writing and frequently sought out Jarrell's input regarding his poems before he published them. In a letter to Jarrell from 1957, Lowell wrote, "I suppose we shouldn't swap too many compliments, but I am heavily in your debt."
Robert Lowell