diff --git a/join.go b/join.go
new file mode 100644
index 0000000..e657e76
--- /dev/null
+++ b/join.go
@@ -0,0 +1,86 @@
+package lipgloss
+
+import (
+	"strings"
+
+	"github.com/muesli/reflow/ansi"
+)
+
+type JoinType int
+
+const (
+	JoinTop JoinType = iota
+	JoinMiddle
+	JoinBottom
+)
+
+// Join is a utility function for horizontally joining two potentially
+// multi-lined strings along a vertical axis.
+//
+// Example:
+//
+//     blockB := "...\n...\n..."
+//     blockA := "...\n...\n...\n...\n..."
+//     fmt.Println(lipgloss.Join(blockA, blockB, lipgloss.AlignTop))
+//
+func Join(left, right string, joinType JoinType) string {
+	l, leftWidth := getLines(left)
+	r, rightWidth := getLines(right)
+
+	// Add extra lines to make each side the same height
+	if len(l) != len(r) {
+		extraLines := make([]string, abs(len(l)-len(r)))
+
+		switch joinType {
+		case JoinMiddle:
+			// Note: we add the remainder to the bottom.
+			half := len(extraLines) / 2
+			start := extraLines[half:]
+			end := extraLines[:half]
+			if len(l) < len(r) {
+				l = append(start, l...)
+				l = append(l, end...)
+				break
+			}
+			r = append(start, r...)
+			r = append(r, end...)
+
+		case JoinBottom:
+			if len(l) < len(r) {
+				l = append(extraLines, l...)
+				break
+			}
+			r = append(extraLines, r...)
+
+		default: // JoinTop
+			if len(l) < len(r) {
+				l = append(l, extraLines...)
+				break
+			}
+			r = append(r, extraLines...)
+
+		}
+	}
+
+	// Merge lines
+	var b strings.Builder
+	for i := range l {
+		b.WriteString(l[i])
+		b.WriteString(strings.Repeat(" ", leftWidth-ansi.PrintableRuneWidth(l[i])))
+		b.WriteString(r[i])
+		b.WriteString(strings.Repeat(" ", rightWidth-ansi.PrintableRuneWidth(r[i])))
+		if i < len(l) {
+			b.WriteRune('\n')
+		}
+	}
+
+	return b.String()
+}
+
+// Return the absolute value of an integer.
+func abs(n int) int {
+	if n < 0 {
+		return -n
+	}
+	return n
+}