The London 2012 gold medallist arrived in a blaze of publicity and made a much-anticipated debut against Reading in early November.
She scored two goals in five appearances, playing the full 90 minutes just once.
The 31-year-old striker told the Spurs website, “I will be forever grateful to the Club, my team-mates and Spurs supporters for taking such good care of me and my family.
“From the moment I arrived in London, I realised I was part of a first-class organisation, one that helped provide me the opportunity to immerse myself back into the game I love.
“Thank you to everyone who helped make this chapter in my soccer journey so special... COYS.”
Tottenham's head of women's football Heather Cowan added, “We wish Alex all the best for the future both at club and international level as she prepares to return back home with her family. She will always be welcome here at Spurs.”
Morgan returns home
The USWNT star admitted that it was a last-minute decision to go to Spurs and play her way back to fitness after the birth of her daughter Charlie in May.
Morgan travelled to London with Charlie with husband Servando Carrasco, who plays professional football with Fort Lauderdale CF in USL League One, arriving later.
"I wasn't sure if I was ready to make the move with my daughter and pull my family apart from each other," she told the BBC at the time.
It was completely up to Morgan whether she would stay in North London beyond Christmas, and now she has decided to return to the warmer climes of Florida.
Alex Morgan at Tottenham
While it was short, Morgan's spell at Tottenham was mutually beneficial with the star player regaining fitness and helping raise the club's profile.
However, her first major contribution was a decisive missed penalty against North London rivals Arsenal in the League Cup on 18 November.
Both the Olympic champion's goals in her time at Spurs came from the spot, her first in the 3-1 win over Brighton on 8 December.
Her second was five days later in another 3-1 victory, this time against Aston Villa.
Cowan continued, “We were delighted at the start of the season when Alex chose us as her Club to help regain fitness and take her first steps back into competitive football after giving birth earlier this year.
"It has been a pleasure to have Alex with us during this period and the whole squad has taken a lot from working every day with someone at the top of the women's game."
The striker was the only one of the three to be selected to play in the USWNT's friendly against the Netherlands on 27 November in Breda, coming on at half-time in a 2-0 win.
It was their first match for 261 days due to the COVID pandemic.