Remarriage is a marriage that takes place after a previous marital union has ended, as through divorce or widowhood. Some individuals are more likely to remarry than others; the likelihood can differ based on previous relationship status (e.g. divorced vs. widowed), level of interest in establishing a new romantic relationship, gender, culture, and age among other factors. Those who choose not to remarry may prefer alternative arrangements like cohabitation or living apart together. Remarriage also provides mental and physical health benefits. However, although remarried individuals tend to have better health than individuals who do not repartner, they still generally have worse health than individuals who have remained continuously married. Remarriage is addressed differently in various religions and denominations of those religions. Someone who repeatedly remarries is referred to as a serial wedder.

As of 1995, depending on individual and contextual factors, up to 50% of couples in the USA ended their first marriage in divorce or permanent separation (i.e. the couple is not officially divorced but they no longer live together or share assets). Couples typically end their marriage because they are unhappy during the partnership; however, while these couples give up hope for their partner, this does not mean they give up on the institution of marriage. The majority of people who have divorced (close to 80%) go on to marry again. On average, they remarry just under 4 years after divorcing; younger adults tend to remarry more quickly than older adults. For women, just over half remarry in less than 5 years, and by 10 years after a divorce 75% have remarried.

People may be eager to remarry because they do not see themselves as responsible for the previous marriage ending. Generally, they are more likely to believe their partner's behaviors caused the divorce, and minimize the influence of their own actions. Therefore, they remain optimistic that a new partnership will lead to better results.

According to data analyzed by USA Today in 2013, remarriage rates in the United States have dropped by 40 percent over the last 20 years.

Many factors influence the likelihood of remarrying after a divorce. Based on the 2006 census, men remarry more often than women. Remarriage rates also differ by ethnicity; remarriage is most common among white women, while black women have the lowest probability of marrying again. Age is another determining factor; women who are older than 25 at the time of divorce are less likely to remarry than women who are younger at the time of marital dissolution. Having children is associated with higher rates of remarriage for men and women. Remarriage also differs by community setting. Women from urban areas or areas with a greater proportion of women who never married are less likely to marry again. Some environmental factors do not affect all ethnicities: only non-white women from communities with high unemployment and poverty have reduced likelihood of remarriage.

Some women enter cohabiting relationships after a divorce instead of remarrying. This pattern of cohabiting after a divorce is more likely for white than black women, for women without religious affiliation, with few or no children, and who live in more economically stable communities.

On the whole, remarriages are associated with greater socioeconomic security and life satisfaction compared to remaining divorced or separated. People who remarry tend to have better adjustment to their divorce, reporting more positive evaluations of their lives compared to divorced individuals who remain single. While divorced couples have a higher risk of developing a wide range of physical and mental health problems, remarrying may attenuate, but not eliminate, some of these health risks. Second Marriages: Triumph of decision over hope? It is often assumed that second marriages are riskier than first marriages - “The triumph of hope over experience” as popularised by Samuel Johnson in 1791. A new analysis of data commissioned from the Office for National Statistics (ONS) challenges this assumption. In fact, second marriages overall do consistently better than first marriages. Where one or both spouses are marrying for the second time, couples marrying today face an estimated 31% risk of divorce during their lifetime, compared to an estimated 45% risk of divorce amongst couples where both spouses are marrying for the first time. However, second marriages do not always fare any better than the first. Again the rates of divorce and separation vary based on demographic and social factors. Second marriage disruptions are more likely for Black women and for women in communities that are less economically well off. Conversely, rates of divorce decline as age at the time of second marriage increases. Also, women who enter their second marriage with no children are generally more likely to sustain their marriages.

There are several reasons why second marriages can be more vulnerable to disruption. Partners bring the same personal qualities to their subsequent marriage as they had during the first, but some of these qualities may have contributed to the first marriage's problems. People who have divorced and remarried multiple times tend to be relatively impulsive and nonconformist. In second marriages, partners also often have to deal with additional complications that do not exist in first marriages, like combining families. Remarriages involving stepchildren have a greater rate of dissolution than those without.