I'm in Love with a Capital "U"

{{Infobox song

| name = I'm in Love with a Capital "U"

| cover = iminlovewithacapitalu.jpg

| alt =

| type = single

| artist = Joe Diffie

| album = Third Rock from the Sun

| B-side = Wild Blue Yonder

| released = May 27, 1995

| format =

| recorded =

| studio =

| venue =

| genre = Country

| length = 3:17

| label = Epic

| writer = Paul Nelson, Craig Wiseman

| producer = Johnny Slate, Joe Diffie

| prev_title = So Help Me Girl

| prev_year = 1995

| next_title = That Road Not Taken

| next_year = 1995

}}

"I'm in Love with a Capital "U"" is a song recorded by American country music artist Joe Diffie. It was released in May 1995 as the fourth single from the album Third Rock from the Sun. The song reached #21 on the Billboard Hot Country Singles & Tracks chart.{{cite book |title= Hot Country Songs: 1944-2012, Eighth edition|last=Whitburn |first=Joel |author-link=Joel Whitburn |publisher=Record Research |year=2013 |page=101}} The song was written by Paul Nelson and Craig Wiseman.